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.