A 9-month-old infant has symmetrical vesiculobullous and eczematous dermatitis around the mouth, anus and on the hands and feet, together with alopecia, photophobia and chronic diarrhea. Serum alkaline phosphatase is low for age. Which of the following is the MOST likely diagnosis?
- A Langerhans cell histiocytosis
- B Kwashiorkor
- C Acrodermatitis enteropathica ✓
- D Biotinidase deficiency
Correct answer: C. Acrodermatitis enteropathica
Explanation
Acrodermatitis enteropathica is an inherited defect of intestinal zinc absorption presenting with periorificial and acral dermatitis, alopecia, diarrhea and secondary infection. Serum alkaline phosphatase is low because zinc is a cofactor for this enzyme, a useful corroborating clue. Langerhans cell histiocytosis can mimic the rash but does not lower alkaline phosphatase, and biotinidase deficiency adds seizures and ataxia rather than this distribution of lesions.
Reference: Nelson Textbook of Pediatrics, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.