Neonatal lupus erythematosus presenting as a non-bullous histiocytoid neutrophilic dermatosis.

Histopathologic findings in neonatal lupus erythematosus (NLE) are usually congruent with those of subacute cutaneous lupus erythematosus. However, neutrophilic dermatosis-type histopathologic features are being increasingly recognized in the literature including rare cases with variant histiocytoid morphology. We report the case of a 7-week-old male presenting with figurate erythema. His mother was found to have elevated anti-nuclear antibodies and was positive for anti-SSA/Ro, anti-SSB/La antibodies and Ro52 autoantibodies. The infant had a similar serological profile. Skin biopsy showed a histiocytoid interstitial infiltrate with mild lichenoid features, sparse neutrophils and mild leukocytoclasis. The histiocytoid infiltrate showed prominent CD68, CD163, and myeloperoxidase expression. Isolated clusters of CD123 + histiocytes were also present. This case highlights the rare finding of non-bullous neutrophilic dermatosis with histiocytoid change in neonatal lupus. In neonates presenting with figurate erythemas with morphological histiocytic change on biopsy, NLE should be considered as a differential diagnosis and investigated for accordingly.