Preface

Psoriasis is an autoimmune disease that causes rapid accumulation of skin cells. This accumulation causes well-demarcated, raised, silver-white, scaly lesions to appear on the surface of the skin such as the scalp, elbows and knees, genitalia, and nails. The prevalence of psoriasis in the United States is about 2% of the total population. This disease is always related to other diseases and the affected person may also have one of the following: type 2 diabetes, inflammatory bowel disease, heart disease, psoriatic arthritis, anxiety, or depression. This book reviews recent literature on the most significant and important studies about psoriasis, the immunological mechanisms involved, the latest dermoscopic and diagnostic methods, and recent methods of treatments. This book includes three sections and eight chapters.

Section 1: "Clinical Criteria, Differential Diagnosis and Comorbidities"

Chapter 1: "The Clinical Characteristics and Treatment Status of Psoriatic Arthritis"

Psoriatic arthritis (PsA) is a complex musculoskeletal disorder. Its clinical features include psoriasis, peripheral arthritis, spinal involvement, enthesitis, and dactylitis. Typically, skin lesions precede osteoarticular lesions, although osteoarticular lesions can precede skin lesions in some cases. This chapter investigates the onset pattern of PsA, the time interval between the occurrence of skin and osteoarticular lesions, and the treatment status of PsA. The study presented in this chapter included sixty-four patients with PsA who had been assessed according to the CASPAR criteria. Of those patients, 75% had a typical lesion-onset pattern where skin lesions preceded osteoarticular lesions (skin leading) and 16% had an osteoarticular-leading lesion pattern. The mean time interval between the onset of lesions in patients with the skin-leading pattern was 14.2 years and that in patients with the osteoarticular-leading pattern was 4.5 years. Non-steroidal anti-inflammatory drugs were prescribed to 39% of patients, conventional synthetic disease-modifying antirheumatic drugs (DMARDs) to 64%, and biologic DMARDs to 51.5%. Because there were several cases where osteoarticular lesions preceded skin lesions in PsA, the chapter authors suggest care should be taken with regard to oligo- or polyarthritis patients with a negative rheumatoid factor without the presence of skin lesions.

Chapter 2: "Dermoscopic Differential Diagnosis of Psoriasis"

Different clinical subtypes of psoriasis can show distinctive clinical appearances. For example, inverse psoriasis does not have squams and resembles erythema intertrigo and sometimes the erythrodermic variant cannot be distinguished from other erythroderma causes. As such, differential diagnosis of psoriasis should be done carefully to manage the disease appropriately. Histopathological examination is the gold standard technique for diagnosis, but a dermatoscope can also be used. This is a non-invasive and easily applicable diagnostic tool with high specificity. This chapter discusses the dermoscopic differential diagnosis of psoriasis.

Chapter 3: "Psoriasis and Skin Comorbidities"

Psoriasis can have many clinical presentations in patients with different medical backgrounds. Medical specialties such as rheumatology, pathology, and cardiology focus on the systemic inflammatory nature of the psoriatic disease. From a dermatological point of view, skin comorbidities are an important issue that affects therapeutic choice. The common comorbidities with psoriasis include vitiligo, alopecia areata, autoimmune bullous skin diseases like bullous pemphigoid and pemphigus vulgaris, and other skin disorders such as hidradenitis suppurativa, and pityriasis rubra pilaris. One of the most paradoxical relationships is between psoriasis and atopic dermatitis. This chapter discusses and describes various comorbidities of psoriasis.
