Erythemato-Papulo-Squamous Diseases

In 2,147 patients suffering from psoriasis, evaluation of the age of onset revealed two peaks, one occurring at the age of 16 years (female) or 22 years (males) and a second peak at the age of 60 years (female) or 57 years (males). Human lymphocyte antigen (HLA) tissue typing in 112 randomly assigned patients showed that HLA-Cw6, known to be at disequilibrium in psoriasis, is present in 85.3% of patients with early onset. In contrast, 14.7% patients with late onset showed this marker. Parents (father or mother) were affected in approximately half of the patients with early onset and in none belonging to the group with late onset. Furthermore, psoriasis in patients with early onset follows an irregular course and shows a strong tendency to become generalized. On the basis of clearly defined criteria (e.g., age of onset, heritability, and clinical course of disease), nonpustular psoriasis shows two distinct forms, one of which is hereditary, with early onset, and the other is sporadic and occurs in older age.

Acute febrile neutrophilic dermatosis, first described in 1964 by Robert Douglas Sweet, has been termed Sweet's syndrome. Classic Sweet's syndrome occurs in middle-aged women after a nonspecific infection of the respiratory or gastrointestinal tract. Raised erythematous plaques with pseudoblistering and occasionally pustules occur on the face, neck, chest, and extremities, accompanied by fever and general malaise. Involvement of the eyes, joints, and oral mucosa as well as internal manifestations of Sweet's syndrome in the lung, liver, kidneys, and central nervous system has been described. The disease is thought to be a hypersensitivity reaction. Parainflammatory (e.g., infections, autoimmune disorders, vaccination) and paraneoplastic (e.g., hemoproliferative disorders, solid malignant tumors) occurrence is found in approximately 25% of the cases and 2% are associated with pregnancy. Sweet's syndrome responds rapidly to systemic therapy with corticosteroids but recurs in about 25% of the cases. Alternative treatment modalities (e.g., potassium iodide, colchicine, dapsone, clofazimine, cyclosporine) have also been used. This article presents data from 38 patients with Sweet's syndrome and reviews its epidemiology, clinical spectrum, histologic features, laboratory results, differential diagnosis, pathogenic mechanisms, associated diseases, and treatment.