Psoriasis and Other Papulosquamous Disease

Definitions – Psoriasis is the most common chronic papulosquamous disease – The classic lesion of psoriasis is a well-demarcated erythematous plaque with a silvery (micaceous) scale – Removal of the scale commonly results in bleeding (Auspitz sign)

Psoriasis is common (2% of the population) As a chronic inflammatory disease it is associated with systemic disease that might be preventable Cardiovascular disease Obesity and smoking precede the development of moderate to severe psoriasis Early, aggressive treatment might lessen the occurrence of some of the co-morbidities and improve survival

Epidemiology Psoriasis affects roughly 2% of the population Equal sex distribution. Onset is bimodal – Peaks between and years of age, but it can occur at any age from birth to death. Familial cases are not uncommon

Etiology/Pathogenesis Genetic basis for the disease is not fully understood Environmental trigger factors Trauma – Koebner phenomenon Stress Streptococcal infection Drugs – e.g. lithium, beta blockers, possibly antimalarial agents Pustular psoriasis has been associated with the withdrawal of corticosteroid therapy Psoriasis is a disease associated with chronic inflammation and a variety of immunologic and cytokine abnormalities are believed to be related to disease expression

Clinical Variants Psoriasis vulgaris Guttate psoriasis Pustular psoriasis Inverse psoriasis Erythrodermic psoriasis

Psoriatic arthritis Affects between 7 & 21% of patients with psoriasis May occur prior to, concurrent with or subsequent to psoriasis More common in patients with moderate to severe cutaneous disease and those with nail involvement

Psoriasis Vulgaris

Guttate Psoriasis

Pustular Psoriasis Localized pustular psoriasis Generalized pustular psoriasis

Erythrodermic Psoriasis

Koebner Phenomenon

Nail Disease in Psoriasis

Psoriatic Arthritis

Diagnosis of Psoriasis Clinical diagnosis Exclude other papulosquamous diseases and chronic eczemas When the clinical disease is typical, then the histopathological features are also characteristic, however when the disease is atypical the histopathology is often non- specific

Differential Diagnosis Chronic Dermatitis Seborrheic Dermatitis Pityriasis rosea Lupus erythematosus Dermatophyte infection Cutaneous T-cell lymphoma (mycosis fungoides) Lichen planus

Chronic Atopic Dermatitis

Chronic Dermatitis

Pityriasis Rosea

Secondary Syphilis

Cutaneous Lupus Erythematosus

Dermatomyositis

Dermatophyte Infection

Onychomycosis

Cutaneous T-cell Lymphoma