**3. The very common involvement of the scalp**

The estimated prevalence of Psoriasis worldwide is 0.3-5%, depending on ethnic origin (Naldi, 1994; Valdimarsson, 2007). In a retrospective analysis in children was present scalp involvement in 48% on 125 patients by Stefanaki & al. (2011) and in 50.3% on 137 patients (most common initial site affected) by Wu & al. (2010) .

Psoriasis of the scalp is estimated to occur in 40-90% of patients with Psoriasis. Up to 79% of patients with chronic plaque Psoriasis may have scalp involvement (Farber & Nall, 1992). It can be mild to severe, frequently itchy and so cosmetically embarrassing to affect patient's QOL adversely. Treatment is often prolonged for a long period of time and can be another cause of worsening of patient's QOL because of hair staining, face irritating, messy, timeconsuming and cosmetically unacceptable applications prescribed.

As with Psoriasis elsewhere on the body, skin cells grow too quickly on the scalp and cause red lesions to be covered with scales. Scalp Psoriasis can be very mild with slight and fine scaling but can also be severe with thick, crusted plaques covering the entire scalp. Psoriasis can extend beyond the hairline onto the forehead, the back of the neck and around the ears.

The scalp is frequently involved in patients with Psoriasis vulgaris but rarely it is the only site affected. Lesions look like an erythematous crown with net margins covered by dry silvery-white scales. They are located at the hairline in the fronto-temporal, parietal or occipital areas (where, often, the erythematous component is more pronounced) and are associated to scaling-scratching squamous lesions. In the fronto-temporal regions, particularly in young subjects, the spots extend beyond the scalp involving the skin of the forehead and ear. In patients with a long history of scalp Psoriasis the confluence of many spots and the scant evidence of the erythematous component leads to the formation of a real shell that can cover the entire scalp. In other cases, silvery-white scales are seen on a widespread dry pityriasiform furfuracea-like desquamation, sometimes showing follicles. The spots do not produce alopecia and hairs are not incorporated by squamous heaps but in the less restrictive forms the pseudotinea amiantacea can be seen. This lesion, once considered a variant of impetigo, is characterized by the presence of small opaque white adherent scales similar to asbestos, that incorporate the proximal part of the hair shaft.

Psoriasiform lesions localized to the face often represent the extension of scalp lesions to the brow, the temporal regions, the ears and the retroauricular fold where it is observed a tendency to fissures. The involvement of the face in the course of Psoriasis is considered an index of extended or severe disease as in the case of erythrodermic Psoriasis. Rarely small droplike lesion in the face can be seen in case of eruptive Psoriasis; in case of mild forms of Psoriasis Vulgaris (minimal Psoriasis) instead, the eyelid involvement by small patches of whitish scales is characteristic. Psoriasis of the ear is characterized not only by the

The association between Psoriasis and alcoholism represents one of the major psychodermatological issues where a multidisciplinary approach (including dermatologist, psychiatrist, psychologist and others) is crucial for optimal outcome. Psoriasis is associated with an increased risk of comorbidity and mortality compared to the general population. It appears that patients with Psoriasis have a higher prevalence of metabolic disorders such as diabetes, hypertension, obesity, and hyperlipidemia, as well as a higher frequency of cigarette smoking. These concomitant diseases can complicate the treatment of Psoriasis.

The estimated prevalence of Psoriasis worldwide is 0.3-5%, depending on ethnic origin (Naldi, 1994; Valdimarsson, 2007). In a retrospective analysis in children was present scalp involvement in 48% on 125 patients by Stefanaki & al. (2011) and in 50.3% on 137 patients

Psoriasis of the scalp is estimated to occur in 40-90% of patients with Psoriasis. Up to 79% of patients with chronic plaque Psoriasis may have scalp involvement (Farber & Nall, 1992). It can be mild to severe, frequently itchy and so cosmetically embarrassing to affect patient's QOL adversely. Treatment is often prolonged for a long period of time and can be another cause of worsening of patient's QOL because of hair staining, face irritating, messy, time-

As with Psoriasis elsewhere on the body, skin cells grow too quickly on the scalp and cause red lesions to be covered with scales. Scalp Psoriasis can be very mild with slight and fine scaling but can also be severe with thick, crusted plaques covering the entire scalp. Psoriasis can extend beyond the hairline onto the forehead, the back of the neck and around the ears. The scalp is frequently involved in patients with Psoriasis vulgaris but rarely it is the only site affected. Lesions look like an erythematous crown with net margins covered by dry silvery-white scales. They are located at the hairline in the fronto-temporal, parietal or occipital areas (where, often, the erythematous component is more pronounced) and are associated to scaling-scratching squamous lesions. In the fronto-temporal regions, particularly in young subjects, the spots extend beyond the scalp involving the skin of the forehead and ear. In patients with a long history of scalp Psoriasis the confluence of many spots and the scant evidence of the erythematous component leads to the formation of a real shell that can cover the entire scalp. In other cases, silvery-white scales are seen on a widespread dry pityriasiform furfuracea-like desquamation, sometimes showing follicles. The spots do not produce alopecia and hairs are not incorporated by squamous heaps but in the less restrictive forms the pseudotinea amiantacea can be seen. This lesion, once considered a variant of impetigo, is characterized by the presence of small opaque white adherent scales similar to asbestos, that incorporate the proximal part of the hair shaft.

Psoriasiform lesions localized to the face often represent the extension of scalp lesions to the brow, the temporal regions, the ears and the retroauricular fold where it is observed a tendency to fissures. The involvement of the face in the course of Psoriasis is considered an index of extended or severe disease as in the case of erythrodermic Psoriasis. Rarely small droplike lesion in the face can be seen in case of eruptive Psoriasis; in case of mild forms of Psoriasis Vulgaris (minimal Psoriasis) instead, the eyelid involvement by small patches of whitish scales is characteristic. Psoriasis of the ear is characterized not only by the

**3. The very common involvement of the scalp** 

(most common initial site affected) by Wu & al. (2010) .

consuming and cosmetically unacceptable applications prescribed.

involvement of the auricle but also by the involvement of external auditory canal by heaps of scales that can stamp it. Diagnosis of SeboPsoriasis, that is characterised by the presence of yellowish-white unctuous scales can be put when psoriasiform lesions are localized exclusively in seborrheic areas of the face (naso-labial fold, glabella and eyebrows, auricle and retroauricular fold) and are associated with similar lesions of the hairline and the presternal area. This clinic form, on the border between Psoriasis Vulgaris and Seborrheic Dermatitis, is considered a Psoriasis arisen on patches of Seborrheic Dermatitis because of the Koebner phenomenon.

Family history may predispose patients to scalp Psoriasis. In an analysis of Psoriasis genes in an Icelandic patient population, 296 of 1,000 Psoriasis patients experienced onset of Psoriasis on the scalp. Cluster analysis (Karason & al., 2005) of this subset of patients determined that 198 patients fit within 79 families and determined a linkage to chromosome 10. The familial nature of Psoriasis has long been recognized with evident intra and interfamilial variability. Thirty nine individual with Psoriasis (25 men and 14 women) from 9 Tunisian unrelated multiplex families (in Tunisian population the estimated prevalence of Psoriasis is of 3%) were investigated during a study period of 1 year (Ammar & al., 2009). The common form of Psoriasis was discovered in 37 cases. The nails, the scalp, the mucous membranes were involved respectively in 21, 12 and 13 cases. The Psoriasis was severe in 11 cases.

Methods used to diagnose scalp Psoriasis vary in sensitivity, reproducibility, and invasiveness. Recently has been introduced a videodermoscopy scalp Psoriasis severity index (VSCAPSI) for evaluation of scalp Psoriasis (Rossi &al., 2011). This index is particularly useful in mild and moderate forms that often are not clinically appreciable. VSCAPSI takes into account extension of the area of the scalp affected, the presence and morphology of vascular patterns, erythema and desquamation. Videodermoscopy images obtained between November 2009 to June 2010 from 900 participants with various scalp and hair disorders were reviewed for distinguishing features. During the 2010 Italian congress on Psoriasis, in order to assess the reproducibility and efficacy of the VSCAPSI, 146 dermatologists were asked to evaluate 16 videodermoscopy images of scalp Psoriasis using the VSCAPSI. Of the 900 patients, 85 new cases of scalp Psoriasis were diagnosed. The other 815 patients were found to be suffering from different scalp and hair diseases. Of 146 dermatologists, 28 did not recognize erythema, 15 desquamation and 7 the vascular patterns. The VSCAPSI provides an important tool for early diagnosis, differential diagnosis and follow-up and screening.

#### **3.1 Histology of head and neck Psoriasis: Gross findings**

Head and neck Psoriasis (in the form of the so-called Psoriasis vulgaris or plaque type of Psoriasis and guttate Psoriasis) commonly involves the skin surface of the scalp and the face (eyebrow, nose, upper lip, forehead, and hairline) and presents as papules, well-demarcated erythematous plaques with a scaly surface or as papulo-squamous lesions covered by fine silvery-white and loosely adherent scales. The amount and thickness of the scales is variable such are the plaques, ranging in size from few to several centimeters, with coalescence of smaller plaques into larger and sometimes fissured lesions. On the other hand, less thick plaques and less scaly lesions are commonly encountered in children with face psoriatic localization compared with adults. Pustular forms of Psoriasis are rarely described on the

Head and Neck Psoriasis 85

In the pustular form of Psoriasis, such a collection of neutrophils occurs as characteristic macropustules (abscesses), while epidermal and dermal changes are similar to those seen in Psoriasis vulgaris. The so-called eruptive or guttate Psoriasis, with small and numerous red papules and an acute onset on clinical examination, shows similar microscopic findings to

Mucosal localizations show a more variable histological presentation ranging from classic hyperparakeratotic lesions, with thinning of the suprapapillary plate and mixed inflammatory infiltrate with neutrophils exocytosis to mild and quickly self-limited erythematous inflammatory conditions with capillaries engorgement but without microabscess formation. Similar microscopic characteristic are shared by different inflammatory mucosal diseases generally known as psoriasiform mucositis or psoriasiform lesions. In such instances, histological distinction between Psoriasis and other inflammatory mucosal entities cannot be made with confidence unless mucosal lesions are associated to or are coincident with cutaneous psoriatic dermatitis and additional data (family history, HLA

Although the diagnosis of Psoriasis mainly rely on clinical settings, histological evaluation should be used to confirm the diagnosis as well as to evaluate unusual clinical lesions and to exclude benign and malignant conditions that may mimic Psoriasis or may

On the other hand, microscopic findings alone should pose problems in differential diagnosis with other inflammatory disorders as well as in the evaluation of the phase of Psoriasis normally evolving through early, advanced and later lesions with a different

Skin psoriatic manifestations should sometimes require a differential diagnosis from dermatoses such as lichen planopilaris, florid seborrheic dermatitis and discoid lupus

On the other hand, differential diagnosis of oral localization of Psoriasis could also consider Reiter's syndrome, erythema migrans, benign migratory glossitis, oral lichen planus and

Clinical data alone may be inadequate such as the case of Koebner phenomenon that could

In this settings, the macroscopic characteristics of cutaneous psoriatic lesions (well defined elevated lesions, with silvery-white or micaceous scale), the clinical data (symmetrical distribution, Auspitz sign, patient's history reporting itchy, skin scaling and peeling, lesions at site of injury or trauma) and the classic histologic findings may all contribute to a

Oral lichen planus, mainly occurring in adults, appears as bilateral plaques, papules and erythematous-atrophic or ulcerated lesions on the oral mucosa, gingivae (desquamative gingivitis) and tongue. Oral white striations (so-called Wickham striae) may coincide with cutaneous lesions on the scalp, laryngeal and esophageal mucosa or less frequent

other inflammatory conditions generally described as psoriasiform lesions.

that of early Psoriasis vulgaris lesions unless the same degree of achantosis.

typing) are available.

be associated to it.

erythematosus.

be present in lichen planus.

definitive diagnosis of Psoriasis.

**3.3 Differential diagnosis** 

microscopic variability with lesion's age and activity.

face as annular or circinnate and pustular lesions on an erythematous background with an acute, subacute or chronic clinical course. Pustular eruptions are frequently associated with a classic form of skin Psoriasis, and both hair loss and involvement of tongue mucosal surface may be appreciated. Oral localizations, less commonly observed in children than in adults, appear as pustular and hyperemic lesions within a geographic and fissured tongue. In such a localization, infections, smoking and physical agents all may affect the course and duration of Psoriasis and may cause dysphagia. Unusual mucosal (nose, oral cavity) or ocular localizations are commonly described in patients with otherwise usual skin psoriatic dermatitis. Mucosal lesions show a non-specific macroscopic appearance ranging from erythematous and slightly raised lesions to a white annular, serpiginous and ulcerated pattern that may disappear quickly, with no obvious clinical symptoms, or may have exacerbations and remissions similar to skin lesions. Pustular forms, mixed white and erythematous lesions, ulcerative, vescicular and indurated lesions, multiple annular coinsized lesions, gray, yellowish, translucent and silvery-white forms are described with macroscopic findings similar to several so-called psoriasiform benign and malignant conditions involving the oral cavity. In this setting, the diagnosis mainly rely on an interdisciplinary clinical and histological approach with a crucial role played by the microscopic findings on mucosal biopsy. Psoriasis vulgaris may also be associated to oral localizations such as the case of geographic tongue and the stomatitis areata migrans. Patients with Psoriasis rarely develop uncommon ocular manifestations such as uveitis, blepharitis and conjunctivitis as a result of changes, alterations and dysfunctions of conjunctival surface, tear film and meibomiam gland changes.

#### **3.2 Microscopic findings**

Variabilities in clinical macroscopic findings of Psoriasis reflect different histologic pictures with relation to the stage of the disease. Generally, early stages show more typical and pathognomonic microscopic clues to the diagnosis than that of the advanced and fully developed lesions. Moreover, histologic differences could also be noted in psoriatic lesions affecting mucosal surfaces.

In its classic histologic appearance, cutaneous Psoriasis shows achantosis (thickened of epidermal layers) and parakeratosis (retention of cell nuclei in stratum corneum) of the epidermis, with thin or loss of granular cell layer, downward elongation of rete ridges and thinning of the epidermis overlying the dermal papillae that shows edema and small vessels close to the epidermis. The latter condition underlies the so-called Auspitz sign: when the silvery scales (parakeratotic layers) are removed from the plaque (epidermal achantosis), small pinpoint bleeding (from dermal capillaries) is seen.

The inflammatory cutaneous infiltrate of Psoriasis is characterized by neutrophils and lymphocytes throughout the superficial papillary dermis. Activated CD3+ T cells are mainly observed around small papillary vessels and are admixed with neutrophils and macrophages. Neutrophils and lymphocytes can migrate upwards from the dermis to the epidermis and in parakeratotic layers (exocytosis). Collections of intraepithelial neutrophils (Munro abscesses) and those arranged in the epidermis in a network of degenerated keratinocytes (spongiform pustule of Kogoj) are characteristics of Psoriasis but not always present nor specific to the disease.

face as annular or circinnate and pustular lesions on an erythematous background with an acute, subacute or chronic clinical course. Pustular eruptions are frequently associated with a classic form of skin Psoriasis, and both hair loss and involvement of tongue mucosal surface may be appreciated. Oral localizations, less commonly observed in children than in adults, appear as pustular and hyperemic lesions within a geographic and fissured tongue. In such a localization, infections, smoking and physical agents all may affect the course and duration of Psoriasis and may cause dysphagia. Unusual mucosal (nose, oral cavity) or ocular localizations are commonly described in patients with otherwise usual skin psoriatic dermatitis. Mucosal lesions show a non-specific macroscopic appearance ranging from erythematous and slightly raised lesions to a white annular, serpiginous and ulcerated pattern that may disappear quickly, with no obvious clinical symptoms, or may have exacerbations and remissions similar to skin lesions. Pustular forms, mixed white and erythematous lesions, ulcerative, vescicular and indurated lesions, multiple annular coinsized lesions, gray, yellowish, translucent and silvery-white forms are described with macroscopic findings similar to several so-called psoriasiform benign and malignant conditions involving the oral cavity. In this setting, the diagnosis mainly rely on an interdisciplinary clinical and histological approach with a crucial role played by the microscopic findings on mucosal biopsy. Psoriasis vulgaris may also be associated to oral localizations such as the case of geographic tongue and the stomatitis areata migrans. Patients with Psoriasis rarely develop uncommon ocular manifestations such as uveitis, blepharitis and conjunctivitis as a result of changes, alterations and dysfunctions of

Variabilities in clinical macroscopic findings of Psoriasis reflect different histologic pictures with relation to the stage of the disease. Generally, early stages show more typical and pathognomonic microscopic clues to the diagnosis than that of the advanced and fully developed lesions. Moreover, histologic differences could also be noted in psoriatic lesions

In its classic histologic appearance, cutaneous Psoriasis shows achantosis (thickened of epidermal layers) and parakeratosis (retention of cell nuclei in stratum corneum) of the epidermis, with thin or loss of granular cell layer, downward elongation of rete ridges and thinning of the epidermis overlying the dermal papillae that shows edema and small vessels close to the epidermis. The latter condition underlies the so-called Auspitz sign: when the silvery scales (parakeratotic layers) are removed from the plaque (epidermal achantosis),

The inflammatory cutaneous infiltrate of Psoriasis is characterized by neutrophils and lymphocytes throughout the superficial papillary dermis. Activated CD3+ T cells are mainly observed around small papillary vessels and are admixed with neutrophils and macrophages. Neutrophils and lymphocytes can migrate upwards from the dermis to the epidermis and in parakeratotic layers (exocytosis). Collections of intraepithelial neutrophils (Munro abscesses) and those arranged in the epidermis in a network of degenerated keratinocytes (spongiform pustule of Kogoj) are characteristics of Psoriasis but not always

conjunctival surface, tear film and meibomiam gland changes.

small pinpoint bleeding (from dermal capillaries) is seen.

**3.2 Microscopic findings** 

affecting mucosal surfaces.

present nor specific to the disease.

In the pustular form of Psoriasis, such a collection of neutrophils occurs as characteristic macropustules (abscesses), while epidermal and dermal changes are similar to those seen in Psoriasis vulgaris. The so-called eruptive or guttate Psoriasis, with small and numerous red papules and an acute onset on clinical examination, shows similar microscopic findings to that of early Psoriasis vulgaris lesions unless the same degree of achantosis.

Mucosal localizations show a more variable histological presentation ranging from classic hyperparakeratotic lesions, with thinning of the suprapapillary plate and mixed inflammatory infiltrate with neutrophils exocytosis to mild and quickly self-limited erythematous inflammatory conditions with capillaries engorgement but without microabscess formation. Similar microscopic characteristic are shared by different inflammatory mucosal diseases generally known as psoriasiform mucositis or psoriasiform lesions. In such instances, histological distinction between Psoriasis and other inflammatory mucosal entities cannot be made with confidence unless mucosal lesions are associated to or are coincident with cutaneous psoriatic dermatitis and additional data (family history, HLA typing) are available.

### **3.3 Differential diagnosis**

Although the diagnosis of Psoriasis mainly rely on clinical settings, histological evaluation should be used to confirm the diagnosis as well as to evaluate unusual clinical lesions and to exclude benign and malignant conditions that may mimic Psoriasis or may be associated to it.

On the other hand, microscopic findings alone should pose problems in differential diagnosis with other inflammatory disorders as well as in the evaluation of the phase of Psoriasis normally evolving through early, advanced and later lesions with a different microscopic variability with lesion's age and activity.

Skin psoriatic manifestations should sometimes require a differential diagnosis from dermatoses such as lichen planopilaris, florid seborrheic dermatitis and discoid lupus erythematosus.

On the other hand, differential diagnosis of oral localization of Psoriasis could also consider Reiter's syndrome, erythema migrans, benign migratory glossitis, oral lichen planus and other inflammatory conditions generally described as psoriasiform lesions.

Clinical data alone may be inadequate such as the case of Koebner phenomenon that could be present in lichen planus.

In this settings, the macroscopic characteristics of cutaneous psoriatic lesions (well defined elevated lesions, with silvery-white or micaceous scale), the clinical data (symmetrical distribution, Auspitz sign, patient's history reporting itchy, skin scaling and peeling, lesions at site of injury or trauma) and the classic histologic findings may all contribute to a definitive diagnosis of Psoriasis.

Oral lichen planus, mainly occurring in adults, appears as bilateral plaques, papules and erythematous-atrophic or ulcerated lesions on the oral mucosa, gingivae (desquamative gingivitis) and tongue. Oral white striations (so-called Wickham striae) may coincide with cutaneous lesions on the scalp, laryngeal and esophageal mucosa or less frequent

Head and Neck Psoriasis 87

psoriatic lesions along with keratinocytes activation and expression of molecules involved in cell proliferation. In particular, basal cell and squamous cell carcinomas are frequently

Moreover, malignant conditions should be ruled out as is the case of the rare acrokeratosis paraneoplastica (Bazex syndrome). The disease can be associated with head and neck and upper aerodigestive tract squamous cell carcinomas and differs from Psoriasis in its localizations (erythematous squamous plaques or scaly patches of earlobes, helices and tip of the nose along with similar lesions in the extremities and nail dystrophy) and lack of

Investigators use several physical examination measures to assess clinical features and severity of Psoriasis and psoriatic arthritis (PsA) in clinical trials, clinical registries, and clinical practice; however, no relevant training modules are widely available to teach and standardize the performance of these measures. At a GRAPPA (Group for Research and Assessment of Psoriasis and Psoriatic Arthritis) meeting adjacent to the 2009 International Federation of Psoriasis Associations in Stockholm, members were updated on the development status of online training videos of Psoriasis and PsA examination measures. Dermatology assessment modules include the PASI, the PGA, the BSA, the original and modified Nail Psoriasis Severity Index (NPSI), the Palmar-Plantar Pustular Psoriasis Area and Severity Index (PPP-PASI), and the PSSI. Rheumatology modules include assessment of tender and swollen joint counts used in the American College of Rheumatology criteria, Disease Activity Score, and other composite arthritis scores; enthesitis assessment used in various enthesitis scoring systems; dactylitis; and spine disease. Each module will include background information for each measure, diagrams and photographs to emphasize teaching points, demonstration video of examination where applicable, and an optional examination at the end. Future plans include evaluating the modules for their influence on interrater and intrarater reliability and development of additional modules (Callis Duffin &

Head and neck Psoriasis treatment is still a challenge because its difficult to get topical agents through hair to be absorbed by the scalp. In fact, scalp is not susceptible to many topical Psoriasis treatment or phototherapy because hair prevent adequate contact with the affected tissue. Moreover current therapies can only bring some relief to the symptoms without any cure to the disease and treatments can carry important side effects in face of

Medications for scalp Psoriasis include those to be left on the scalp and wash off products. Left on products are gels, lotions and ointments containing steroids, coal tar, salicylic acid or

Wash off products are shampoos containing coal tar, salicylic acid, sulfur, selenium, ketoconazole or zinc pyrithione. Recently, Handa (2010) proposed a treatment algorithm for

In 2009 van de Kerkhof & al. divided treatment of scalp Psoriasis into four phases. First phase involves descaling using salicylic acid or urea preparations. The second phase is the

scalp Psoriasis (see Tab. 1), dividing a first line and a second line therapies.

reported and should be taken into account when evaluating psoriatic patients.

histological findings typical of Psoriasis.

**4. The difficulty of the treatment** 

Mease, 2011).

high therapeutic costs.

vitamin D analogs.

conjunctival lesions. Skin involvement of the scalp (lichen plano-pilaris) appears as scarring alopecia and violaceous and erythematous papules with hair loss. On histologic examination, more irregular acanthosis, prominent granular cell layer and dense subepithelial T-cell CD8+ inflammatory infiltrate along with damage of basal keratinocytes represent clues to the diagnosis in contrast to Psoriasis. Moreover, since patients with oral lichen planus could develop oral squamous cell carcinoma and commonly show a significant local morbidity with negative impact on QOL, a proper diagnosis based on clinical and histological findings is mandatory.

Discoid lupus erythematosus may sometimes be responsible for unusual manifestations in head and neck localizations that can mimic several skin diseases (Psoriasis, acne rosacea, lichen planopilaris) or be associated with liken planus-like lesions and Psoriasis. Nonetheless, clinical findings are usually characteristic as erythematous papules and plaques that progress to scaling lesions with pigmentary changes (central hypopigmentation and peripheral hyperpigmentation) in a centrifugal spread. Cutaneous scalp lesions may result in permanent alopecia with atrophy and scarring (localized form of discoid lupus erythematosus) with histologic picture similar to that of lichen planopilaris. Rare mucosal involvement are described with clinical and microscopic characteristic that may simulate lichen planus lesions. In this setting, laboratory data (hematologic and serologic abnormalities frequently observed in widespread discoid lupus erythematosus) along with meticulous clinical attention and microscopic findings (essentially dependent on familiarity with these lesions) can pose a correct diagnosis.

Psoriatic lesions may also not look much different from those caused by seborrheic dermatitis, a papulo-squamous disease of the scalp, face and trunk. In its facial localization, the disease may be associated with squamous blepharitis, a chronic inflammation of the lid margins with small white scales accumulated among the lashes, or may present as mild scaling to widespread crust adherent to the skin of the scalp, forehead, neck and postauricolar skin. Secondary infections may occur as eczematoid dermatitis. Microscopic picture shows a more irregular acanthosis than that seen in psoriatic lesions along with spongiosis and follicular ostia involvement.

The guttate variety of Psoriasis may appears as an acute exanthema in young adults, often associated to streptococcal pharyngitis, with papules on the face similar to those seen in psoriasiform drug eruption. The latter condition is also known as localized drug reactions related to medications and usually involving the face, chest and back with a papuloerythematous or vescicular and pustular appearance. Similarly, psychogenic and emotional factors, infections and environmental factors may all contribute to the development of cutaneous lesions similar to those seen in Psoriasis or may be related to increase in Psoriasis activity and severity.

Histologic overlapping in such cases, with lacking of microscopic characteristic features, require a correct clinical evaluation in the differential diagnosis of these conditions.

Differential diagnosis of head and neck Psoriasis, in both cutaneous and mucosal localizations, should also consider preneoplastic and neoplastic conditions. Since head and neck Psoriasis is more often a chronic and long standing process, frequently associated with severe cutaneous disease and difficult treatment, a significant risk of cancer has been noted. Such an association could be related to the reactive epidermal hyperproliferation seen in

conjunctival lesions. Skin involvement of the scalp (lichen plano-pilaris) appears as scarring alopecia and violaceous and erythematous papules with hair loss. On histologic examination, more irregular acanthosis, prominent granular cell layer and dense subepithelial T-cell CD8+ inflammatory infiltrate along with damage of basal keratinocytes represent clues to the diagnosis in contrast to Psoriasis. Moreover, since patients with oral lichen planus could develop oral squamous cell carcinoma and commonly show a significant local morbidity with negative impact on QOL, a proper diagnosis based on

Discoid lupus erythematosus may sometimes be responsible for unusual manifestations in head and neck localizations that can mimic several skin diseases (Psoriasis, acne rosacea, lichen planopilaris) or be associated with liken planus-like lesions and Psoriasis. Nonetheless, clinical findings are usually characteristic as erythematous papules and plaques that progress to scaling lesions with pigmentary changes (central hypopigmentation and peripheral hyperpigmentation) in a centrifugal spread. Cutaneous scalp lesions may result in permanent alopecia with atrophy and scarring (localized form of discoid lupus erythematosus) with histologic picture similar to that of lichen planopilaris. Rare mucosal involvement are described with clinical and microscopic characteristic that may simulate lichen planus lesions. In this setting, laboratory data (hematologic and serologic abnormalities frequently observed in widespread discoid lupus erythematosus) along with meticulous clinical attention and microscopic findings (essentially dependent on familiarity

Psoriatic lesions may also not look much different from those caused by seborrheic dermatitis, a papulo-squamous disease of the scalp, face and trunk. In its facial localization, the disease may be associated with squamous blepharitis, a chronic inflammation of the lid margins with small white scales accumulated among the lashes, or may present as mild scaling to widespread crust adherent to the skin of the scalp, forehead, neck and postauricolar skin. Secondary infections may occur as eczematoid dermatitis. Microscopic picture shows a more irregular acanthosis than that seen in psoriatic lesions along with

The guttate variety of Psoriasis may appears as an acute exanthema in young adults, often associated to streptococcal pharyngitis, with papules on the face similar to those seen in psoriasiform drug eruption. The latter condition is also known as localized drug reactions related to medications and usually involving the face, chest and back with a papuloerythematous or vescicular and pustular appearance. Similarly, psychogenic and emotional factors, infections and environmental factors may all contribute to the development of cutaneous lesions similar to those seen in Psoriasis or may be related to increase in Psoriasis

Histologic overlapping in such cases, with lacking of microscopic characteristic features,

Differential diagnosis of head and neck Psoriasis, in both cutaneous and mucosal localizations, should also consider preneoplastic and neoplastic conditions. Since head and neck Psoriasis is more often a chronic and long standing process, frequently associated with severe cutaneous disease and difficult treatment, a significant risk of cancer has been noted. Such an association could be related to the reactive epidermal hyperproliferation seen in

require a correct clinical evaluation in the differential diagnosis of these conditions.

clinical and histological findings is mandatory.

with these lesions) can pose a correct diagnosis.

spongiosis and follicular ostia involvement.

activity and severity.

psoriatic lesions along with keratinocytes activation and expression of molecules involved in cell proliferation. In particular, basal cell and squamous cell carcinomas are frequently reported and should be taken into account when evaluating psoriatic patients.

Moreover, malignant conditions should be ruled out as is the case of the rare acrokeratosis paraneoplastica (Bazex syndrome). The disease can be associated with head and neck and upper aerodigestive tract squamous cell carcinomas and differs from Psoriasis in its localizations (erythematous squamous plaques or scaly patches of earlobes, helices and tip of the nose along with similar lesions in the extremities and nail dystrophy) and lack of histological findings typical of Psoriasis.

Investigators use several physical examination measures to assess clinical features and severity of Psoriasis and psoriatic arthritis (PsA) in clinical trials, clinical registries, and clinical practice; however, no relevant training modules are widely available to teach and standardize the performance of these measures. At a GRAPPA (Group for Research and Assessment of Psoriasis and Psoriatic Arthritis) meeting adjacent to the 2009 International Federation of Psoriasis Associations in Stockholm, members were updated on the development status of online training videos of Psoriasis and PsA examination measures. Dermatology assessment modules include the PASI, the PGA, the BSA, the original and modified Nail Psoriasis Severity Index (NPSI), the Palmar-Plantar Pustular Psoriasis Area and Severity Index (PPP-PASI), and the PSSI. Rheumatology modules include assessment of tender and swollen joint counts used in the American College of Rheumatology criteria, Disease Activity Score, and other composite arthritis scores; enthesitis assessment used in various enthesitis scoring systems; dactylitis; and spine disease. Each module will include background information for each measure, diagrams and photographs to emphasize teaching points, demonstration video of examination where applicable, and an optional examination at the end. Future plans include evaluating the modules for their influence on interrater and intrarater reliability and development of additional modules (Callis Duffin & Mease, 2011).
