Erythroderma

Erythroderma, also known as generalized exfoliative dermatitis, is a clinical syndrome defined by widespread redness of the skin with diffuse scaling, usually involving most of the body surface area. Patients commonly have itching, warmth, and edema; fever, malaise, and swollen lymph nodes may occur. The skin may become fragile, and patients can develop secondary infections or electrolyte imbalances due to impaired skin barrier and fluid loss.

Most cases arise from an underlying condition rather than being a primary skin disease. Common causes include chronic inflammatory dermatoses such as psoriasis or atopic dermatitis, severe dermatitis, or pityriasis rubra pilaris; drug reactions (for example to anticonvulsants, allopurinol, antibiotics), and less commonly malignancies such as cutaneous T-cell lymphoma (Sezary syndrome).

Evaluation starts with a detailed history (onset, drug exposures, recent infections, fever) and thorough skin examination. A skin biopsy helps classify the histopathology and guide treatment. Laboratory studies often show elevated inflammatory markers, possible anemia, electrolyte disturbances, and hypoalbuminemia in severe cases. Additional tests may be needed to identify infection or detect systemic disease.

Management focuses on treating the underlying cause and supporting the patient. General skin care includes gentle cleansing, frequent emollients, and avoiding irritants. In drug-induced erythroderma, stopping the offending medication is essential. Hospitalization is often required for fluid and temperature management and to monitor for infection. Treatments may include systemic therapies selected for the underlying condition (for example, methotrexate, cyclosporine, retinoids, or targeted biologics for inflammatory dermatoses or CTCL), and symptomatic measures such as antihistamines for pruritus. The prognosis depends on etiology and the presence of complications; infection, dehydration, and heart or kidney strain increase risk and can be life-threatening.