Erythroderma: a prospective study of 309 patients followed for 12 years in a tertiary center.

Erythroderma is characterized by erythema and scaling affecting more than 80% of the body surface area. It is potentially life-threatening, and diagnosis of the underlying disease is a challenge. Despite laboratory improvements, many cases remain idiopathic. We aimed to analyze clinical and laboratory findings of 309 erythrodermic patients to find clues to the etiologic diagnosis. We performed a prospective study at the University of São Paulo Medical School, from 2007 to 2018, with patients with acquired erythroderma. Clinical, laboratory, histology, and molecular biology data were collected. The median age at diagnosis was 57 years, with a male-to-female ratio of 2.2. Eczema was the most frequent etiology (20.7%), followed by psoriasis (16.8%), Sézary syndrome (12.3%), drug eruption (12.3%), atopic dermatitis (8.7%), and mycosis fungoides (5.5%). Other diagnoses (6.8%) included pemphigus foliaceous, paraneoplastic erythroderma, adult T-cell leukemia/lymphoma, dermatomyositis, pityriasis rubra pilaris, lichen planus, bullous pemphigoid, and leprosy. In 52 patients (16.8%), it was not possible to elucidate erythroderma etiology. Atopic dermatitis developed erythroderma at an earlier age (median 25 years; P = 0.0001). Acute onset was associated with drug reactions and atopic dermatitis (median time from erythroderma to diagnosis of 1 and 1.5 months, respectively; P = 0.0001). Higher immunoglobulin E levels were observed in atopic dermatitis (median 24,600 U/L; P = 0.0001). Histopathology was helpful and was consistent with the final diagnosis in 72.4%. Monoclonal T-cell proliferation in the skin was observed in mycosis fungoides (33.3%) and Sézary syndrome (90.9%). At the last assessment, 211 patients (69.3%) were alive with disease, 65 (21.7%) were alive without disease, and 27 (9.1%) died with active disease. Erythroderma is a challenging syndrome with a difficult diagnostic approach. Younger age and higher immunoglobulin E levels are associated with atopic dermatitis; acute onset is observed in drug eruptions and atopic dermatitis. Histopathology and molecular biology tests are essential tools in the investigation of erythroderma.

A case report of erythroderma in a patient with borderline leprosy on reversal reaction: a result of the exacerbated reaction?

BACKGROUND: Erythroderma is characterized by erythema and scaling affecting more than 90% of the body surface area. Inflammatory, neoplastic and, more rarely, infectious diseases may culminate with erythroderma. Diagnosis of the underlying disorder is therefore crucial to institute the appropriate therapy. Leprosy is a chronic infectious disease that is endemic in Brazil. Here we present an unusual case of leprosy and reversal reaction causing erythroderma, and we discuss the underlying immunological mechanisms which could contribute to the generalized skin inflammation. CASE PRESENTATION: We report a case of a patient with reversal reaction (RR) in borderline borderline leprosy presenting with erythroderma and neural disabilities. Histopathology of the skin showed regular acanthosis and spongiosis in the epidermis and, in the dermis, compact epithelioid granulomas as well as grouped and isolated bacilli. This duality probably reflects the transition from an anergic/multibacillary state to a state of more effective immunity and bacillary control, typical of RR. Leprosy was successfully treated with WHO's multidrug therapy, plus prednisone for controlling the RR; the erythroderma resolved in parallel with this treatment. Immunologic studies showed in situ predominance of IFNγ + over IL-4+ lymphocytes and of IL-17+ over Foxp3+ lymphocytes, suggesting an exacerbated Th-1/Th-17 immunoreactivity and poor Th-2 and regulatory T-cell responses. Circulating Tregs were also diminished. We hypothesize that the flare-up of anti-mycobacteria immunoreactivity that underlies RR may have triggered the intense inflammatory skin lesions that culminated with erythroderma. CONCLUSIONS: This case report highlights the importance of thorough clinical examination of erythrodermic patients in search for its etiology and suggests that an intense and probably uncontrolled leprosy RR can culminate in the development of erythroderma.