**5. Clinics**

Clinical findings of leprosy are primarily due to skin and nervous system involvement. There are five common types of peripheral nerve changes:

**1.** Enlargement of peripheral nerves: Peripheral nerves are more frequently affected by superficial placement. Unique findings such as anesthesia or hypoesthesia may develop as well as sensitivity and enlargement [55, 57]. Ulnar nerve in the elbow, median and superficial radial cutaneous nerve in the wrist, large common auricular nerve in the neck, and common peroneal nerve enlargement in the popliteal fossa can be detected by palpation [57].

**5.4. Borderline lepromatous leprosy**

**5.5. Lepromatous leprosy**

**Figure 1.** Lower extremity involvement.

and lashes [60].

The immune system is weak enough to stop bacterial proliferation but sufficient to suppress inflammation that causes tissue damage [59]. Clinical findings are considerably diverse. Lepromatous lepra-like weak-edged and tuberculoid lepra-like sharp-edged plaques providing a classical dimorphic annular appearance are seen in only one of three patients [54]. Large plaques with sharp or weak edges and normal papules and nodules on which normal skin islands are visible can also be observed. The number of lesions varies from solitary to multiple. While the annular plaque lesions show asymmetrical placement, the nodules localized symmetrically. Neurological involvement is common and severe sensorimotor damage can be observed.

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Extensive disease is seen due to the inadequate cellular immune response. Classical lesions are characterized by multiple, diffuse, often symmetric, sharply defined papules, plaques and nodules. Involvement areas are usually the face, the hip and the lower extremity (**Figure 1**). The infiltration of the forehead skin leads to generation of lion face, which is a characteristic facial appearance (**Figure 2**). Hair loss is widespread, especially in the eyebrows (madarosis)


Clinical forms of leprosy are determined according to clinical, bacteriological, immunological and histopathological criteria. According to that, leprosy has five clinical types:

#### **5.1. Tuberculoid leprosy**

It is a form of strong immune response that can be followed by spontaneous healing. Primary skin lesions are hairless, faintly elevated and endure, erythematous, squamous, annular plaques, which can be accompanied by neural involvements such as sharp anesthesia and hyperesthesia. The number of lesions is often solitary and does not exceed 10 cm in size. It can be seen as hypopigmented lesions in which partial pigment loss is observed, especially in dark-skinned individuals [54, 58]. Lesions should be examined thoroughly in terms of alopecia. Even if the enlargement and tenderness of the peripheral nerves near the cutaneous lesion are not detected, the lesion itself is typically hyperesthesia and anhidrotic [58].

#### **5.2. Borderline tuberculoid leprosy**

Although the immune response is sufficient to limit the disease, it is insufficient for spontaneous recovery [59]. Patients in this form may have a TT upgrade or borderline leprosy downgrade according to the change in the immunological response. Primary skin lesions are sharply defined, multiple, asymmetric, annular plaques and papules [54]. Lesions are less indurated and eleve, less erythematous, scarless, or slightly squamous than TT. The lesions can be seen in size to cover the entire limb. The lesions can be seen in size to cover the entire extremity. Loss of sense is observed in all lesions and nerve involvement (enlargement and paralysis) is usually asymmetry.

#### **5.3. Mid-borderline leprosy**

Immunologically, the two extremities are the midpoint of the spectrum [59]. The severity of cutaneous findings and neurological changes depend on which end of the patient is closer to. Primer skin lesions are generally asymmetric, alopecic, annular, sharply defined and broad platelets with the appearance of "Swiss cheese" where clinically normal skin islets are found.

#### **5.4. Borderline lepromatous leprosy**

radial cutaneous nerve in the wrist, large common auricular nerve in the neck, and common peroneal nerve enlargement in the popliteal fossa can be detected by palpation [57].

**3.** Sensory and motor function losses may occur depending on the location of nerves that are involved. General neurological examination was performed and neurological changes such as drop foot, flexion contracture 4–5 of the fingers, muscular atrophy, facial paralysis,

**4.** Depending on the influence of thin, unmyelinated Type C fibers responsible for the transmission of senses such as light touch, pain, hot, and cold; the sensory loss in the glove-

**5.** Anaphylaxis of palmoplantar area may be observed by the effected sympathetic nerve

Clinical forms of leprosy are determined according to clinical, bacteriological, immunological

It is a form of strong immune response that can be followed by spontaneous healing. Primary skin lesions are hairless, faintly elevated and endure, erythematous, squamous, annular plaques, which can be accompanied by neural involvements such as sharp anesthesia and hyperesthesia. The number of lesions is often solitary and does not exceed 10 cm in size. It can be seen as hypopigmented lesions in which partial pigment loss is observed, especially in dark-skinned individuals [54, 58]. Lesions should be examined thoroughly in terms of alopecia. Even if the enlargement and tenderness of the peripheral nerves near the cutaneous lesion are not detected,

Although the immune response is sufficient to limit the disease, it is insufficient for spontaneous recovery [59]. Patients in this form may have a TT upgrade or borderline leprosy downgrade according to the change in the immunological response. Primary skin lesions are sharply defined, multiple, asymmetric, annular plaques and papules [54]. Lesions are less indurated and eleve, less erythematous, scarless, or slightly squamous than TT. The lesions can be seen in size to cover the entire limb. The lesions can be seen in size to cover the entire extremity. Loss of sense is observed in all lesions and nerve involvement (enlargement and

Immunologically, the two extremities are the midpoint of the spectrum [59]. The severity of cutaneous findings and neurological changes depend on which end of the patient is closer to. Primer skin lesions are generally asymmetric, alopecic, annular, sharply defined and broad platelets with the appearance of "Swiss cheese" where clinically normal skin islets are found.

**2.** Presence of sensory defects such as anesthesia and hypoesthesia in skin lesions.

stocking pattern may be observed first in the hot-cold discrimination.

and histopathological criteria. According to that, leprosy has five clinical types:

the lesion itself is typically hyperesthesia and anhidrotic [58].

and lagophthalmia may be detected [57].

42 Hansen's Disease - The Forgotten and Neglected Disease

fibers.

**5.1. Tuberculoid leprosy**

**5.2. Borderline tuberculoid leprosy**

paralysis) is usually asymmetry.

**5.3. Mid-borderline leprosy**

The immune system is weak enough to stop bacterial proliferation but sufficient to suppress inflammation that causes tissue damage [59]. Clinical findings are considerably diverse. Lepromatous lepra-like weak-edged and tuberculoid lepra-like sharp-edged plaques providing a classical dimorphic annular appearance are seen in only one of three patients [54]. Large plaques with sharp or weak edges and normal papules and nodules on which normal skin islands are visible can also be observed. The number of lesions varies from solitary to multiple. While the annular plaque lesions show asymmetrical placement, the nodules localized symmetrically. Neurological involvement is common and severe sensorimotor damage can be observed.

#### **5.5. Lepromatous leprosy**

Extensive disease is seen due to the inadequate cellular immune response. Classical lesions are characterized by multiple, diffuse, often symmetric, sharply defined papules, plaques and nodules. Involvement areas are usually the face, the hip and the lower extremity (**Figure 1**). The infiltration of the forehead skin leads to generation of lion face, which is a characteristic facial appearance (**Figure 2**). Hair loss is widespread, especially in the eyebrows (madarosis) and lashes [60].

**Figure 1.** Lower extremity involvement.

**7. Immunologic reactions**

especially may be observed in knees.

patients, the exact diagnosis is made by skin biopsy.

**8. Differential diagnosis**

and sarcoidosis [66].

Immunological reactions are inflammatory conditions that clinicians and patients may encounter before, during, or months or years after treatment [62]. Approximately 30–50% of patients are involved. There are two types of reactions that are linked to different immunological mechanisms that are not fully understood: Type 1 and type 2 [63]. These immunological reactions may mimic the drug reaction, the clinician should pay attention to that they are not drug reactions and that treatment should not be interrupted. In both types of reactions, general weakness, fatigue and fever can be observed. Other clinical findings differ according to the developing reaction.

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*Type 1 reaction:* Typically occurs in TT and BT. It is due to an increase in cell-mediated immunity and a delayed-type hypersensitivity reaction to *M. leprae* antigens [55, 57, 63, 64]. Characteristic clinical findings are increased inflammation in existing lesions, formation of new lesions, pain

*Type 2 reaction:* Typically, BL and LL patients develop when treatment begins. Pregnancy and pyogenic infections may induce. The type 2 reaction due to the formation of immune complex with hyper humoral immunity represents cutaneous and systemic small vessel vasculitis [55]. Characteristic clinical findings; painful nodular lesions (erythema nodosum leprosum) that occur suddenly, severe swelling and pain in the joints, iridocyclitis, orchitis, sensitive lymph-

*Lucio phenomenon* is a rare complication characterized by sudden-onset, necrotizing cutaneous small vessel vasculitis in diffuse, untreated LL patients in the Mexican and Caribbean region [65]. Lesions that are painful but have no increase in temperature can be cured by scarring. Ulceration

Although reduction and absence of sensory perception distinguish leprosy lesions from other diseases, this finding may not always be detectable. With the reason that a wide variety of cutaneous lesions are present, leprosy can be confused with many diseases. In suspected

Hypopigmented lesions may mimic pityriasis alba, pityriasis versicolor, mycosis fungoides

Figured erythematous plaques may be confused with fungal infections, annular psoriasis,

Infiltrated plaques and nodules generate definitive diagnosis with cutaneous leiomyoma,

In addition, definitive diagnosis of type 1 reaction includes acute lupus erythematosus, drug reactions, cellulitis; the definitive diagnosis of the type 2 reaction should be considered to

sarcoidosis, mycosis fungoides, lichen planus, systemic lupus erythematosus [66].

sarcoidosis, syphilis, keloid, cutaneous lymphoma, granuloma annulare [66].

include other conditions that may cause vasculitis and panniculitis.

and sensitivity in nerves (neuritis), progressive neurological failure.

adenopathy, glomerulonephritis, and hepatosplenomegaly [57, 63, 64].

**Figure 2.** Characteristic facial appearance (lion face).
