Follicular Eruption on Arms and Legs—Diagnosis

Findings from the patient's skin biopsy demonstrated distention of the upper follicular ostia with prominent keratotic plugging. The patient's multivitamin supplementation had been recently changed to omit vitamin A. Two-month supplementation increased his serum vitamin A level to 67 μg/dL and resolved his eruption and vision abnormalities.

Phrynoderma is classically thought to result from severe vitamin A deficiency,^1-5 although deficiencies in vitamins B⁶ and E⁷ essential fatty acids and severe malnutrition⁸ have also been implicated. Severe vitamin A deficiency may also result in conjunctival and corneal lesions and nyctalopia (night blindness).¹