A Boy with a Bald Spot

8-year-old Al is in for follow-up of an ear infection, but his mother is more interested in why no hair will grow on that spot on the back of his head.

The young boy's ear infection is resolved and he is otherwise quite healthy for his age. The spot has been there since he was born, the mother reports, and hair has never grown there.Any thoughts on what the cause might be? Follow the case in Dr Jon Schneider's slides above and see if your initial hunch is correct.    

References:

► Galbraith SS. Neonatal dermatology. In: Rudolph CD, Rudolph AR, Lister GE, First LR, Gershon AE, eds. Rudolph’s Pediatrics. 22nd ed. New York, NY: McGraw-Hill; 2011:chap 357.

► Morelli JG. Cutaneous defects. In: Kliegman RM, Stanton BF, St. Geme JW III, Schor NF, Behrman RE, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, PA: Elsevier Saunders; 2011:2220-2222.

► Iljin A, Kruk-Jeromin J. Aplasia cutis congenita. Adv Clin Exp Med. 2010;19:121-125

► Aplasia Cutis Congenita (Medscape; updated 2015)             

► Hair Loss and its Management in Children (Medscape) 
► Nonsyndromic Aplasia Cutis Congenita Genetic Home Reference. (NIH; updated 2013)