Causes and features of erythroderma.

INTRODUCTION Erythroderma is a generalised inflammatory reaction of the skin secondary to a variety of causes. This retrospective study aims to characterise the features of erythroderma and identify the associated causes of this condition in our population. MATERIALS AND METHODS We reviewed the clinical, laboratory, histological and other disease-specific investigations of 225 inpatients and outpatients with erythroderma over a 7.5-year period between January 2005 and June 2012. RESULTS The most common causative factors were underlying dermatoses (68.9%), idiopathic causes (14.2%), drug reactions (10.7%), and malignancies (4.0%). When drugs and underlying dermatoses were excluded, malignancy-associated cases constituted 19.6% of the cases. Fifty-five percent of malignancies were solid-organ malignancies, which is much higher than those previously reported (0.0% to 25%). Endogenous eczema was the most common dermatoses (69.0%), while traditional medications (20.8%) and anti-tuberculous medications (16.7%) were commonly implicated drugs. In patients with cutaneous T-cell lymphoma (CTCL), skin biopsy was suggestive or diagnostic in all cases. A total of 52.4% of patients with drug-related erythroderma had eosinophilia on skin biopsy. Electrolyte abnormalities and renal impairment were seen in 26.2% and 16.9% of patients respectively. Relapse rate at 1-year was 17.8%, with no associated mortality. CONCLUSION Our study highlights the significant proportion of malignancy-related erythroderma in those whom common underlying causes such as dermatoses and drugs have been excluded. In cases of drug-related erythroderma, traditional medications and antituberculous medications are common causes in our population. Renal impairment and electrolyte abnormalities are commonly seen and should be monitored in patients with erythroderma.