Incontinentia pigmenti (Bloch-Sulzberger syndrome) passes through 4 clinical stages. Which of the following correctly pairs the stage with its histopathological finding?

• A Stage 2 (verrucous): subepidermal blistering with dermal fibrosis
• B Stage 3 (pigmented): melanin in melanocytes with absent melanin incontinence
• C Stage 4 (atrophic/hypopigmented): epidermal hyperplasia with hyperkeratosis
• D Stage 1 (vesicular): intraepidermal eosinophilic spongiosis with eosinophil-filled vesicles ✓

Explanation

Incontinentia pigmenti is an X-linked dominant condition caused by IKBKG (NEMO) gene mutation, lethal in males. Stage 1 (vesicular, neonatal): eosinophilic spongiosis with eosinophil-filled intraepidermal vesicles — the characteristic histopathological hallmark. Stage 2 (verrucous, weeks): hyperkeratosis, acanthosis, papillomatosis. Stage 3 (pigmented, months): melanin incontinence with prominent dermal melanophages (hence the 'incontinentia pigmenti' name). Stage 4 (atrophic, years-adults): dermal fibrosis, decreased melanin, loss of appendages. Associated features include retinal dysplasia, dental anomalies, CNS abnormalities, and alopecia. Stages 3 and 4 directly follow the logic of melanin dropping down (incontinence) into the dermis.

Reference: Neena Khanna Illustrated Synopsis of Dermatology & STD, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.