Early skin biopsy is helpful for the diagnosis and management of neonatal and infantile erythrodermas

Background: Erythrodermas are often life‐threatening conditions in infants. Determination of the underlying cause is crucial. Microscopic changes in adult erythroderma lack specificity. Objective: To determine if an early skin biopsy is helpful for the diagnosis of neonatal and infantile erythroderma. Methods: Seventy‐two patients admitted for erythroderma in the first year of life were retrospectively included. One hundred and eleven skin biopsies (12‐year period) were examined by 3 pathologists blinded to the clinical diagnosis, and classified into atopic dermatitis, immunodeficiency (ID), psoriasis, Netherton syndrome (NS), ichthyosis, other. From year 2000, LEKTI antibody was performed when NS was suspected. Pathological diagnosis was then compared with clinical diagnosis. Results: The final diagnosis was made in 69.3% of the cases. In 57.6%, pathological diagnosis was in accordance, and in 11.7%, it was in accordance, but other diagnosis had also been proposed. For ID, sensitivity and specificity were 58.5 and 98.5%, respectively. Before year 2000, NS was frequently misdiagnosed with psoriasis, but with the use of LEKTI antibody, sensitivity and specificity were 100%. Conclusion: Skin biopsy is helpful for etiologic diagnosis of early erythroderma of infancy, particularly in ID and NS, the most severe diseases. Consequently, these results justify an early systematic skin biopsy for a better and earlier management. Leclerc‐Mercier S, Bodemer C, Bourdon‐Lanoy E, Larousserie F, Hovnanian A, Brousse N, Fraitag S. Early skin biopsy is helpful for the diagnosis and management of Neonatal and Infantile Erythrodermas.