Drug-induced subacute cutaneous lupus erythematosus: evidence for differences from its idiopathic counterpart

Drug-induced subacute cutaneous lupus erythematosus (DI-SCLE) is a lupus variant with predominant skin involvement temporally related to drug exposure and resolving after drug discontinuation. It usually presents with annular polycyclic or papulosquamous eruptions on sun-exposed skin and shows serum anti-Ro/SSA antibodies.

To address the question whether DI-SCLE differs significantly from idiopathic SCLE by virtue of clinical features.

Ninety patients with SCLE seen in our departments from 2001 to 2010 were reviewed. Eleven of them diagnosed as having DI-SCLE were evaluated for type of skin lesions, systemic involvement, clinical course, and histopathological, direct immunofluorescence and laboratory findings. The cutaneous features were compared with those of the 79 patients with idiopathic SCLE.

The cutaneous picture was widespread in 82% of patients with DI-SCLE and in 6% of those with idiopathic SCLE [odds ratio (OR) 66·6, 95% confidence interval (CI) 11·2-394·9; P = 0·0001]. Bullous and erythema multiforme (EM)-like lesions were present in 45% of patients with DI-SCLE and in 1% of those with idiopathic SCLE (OR 65·0, 95% CI 6·5-649·6; P = 0·0001). Vasculitic lesions were observed in 45% of patients with DI-SCLE and in 3% of those with idiopathic SCLE (OR 32·1, 95% CI 5·1-201·7; P = 0·0001). Malar rash occurred in 45% of patients with DI-SCLE and in 6% of those with idiopathic SCLE (OR 12·3, 95% CI 2·8-54·9; P = 0·001). Visceral manifestations were excluded in all patients with DI-SCLE. Anti-Ro/SSA antibodies were found in all but one patient with DI-SCLE and disappeared after resolution in 73% of cases.

DI-SCLE differs from idiopathic SCLE by virtue of distinctive cutaneous features, particularly the widespread presentation and the frequent occurrence of malar rash and bullous, EM-like and vasculitic manifestations.