research Extensive Scalp Angioedema Following High-Dose Diphenylcyclopropenone for Alopecia Areata 5 citations, January 2014 in “Hospital pharmacy” Using a strong allergy medicine too often on the scalp can cause swelling and inflammation.
research Follicular Contact Dermatitis Revisited: A Review Emphasizing Neomycin-Associated Follicular Contact Dermatitis 9 citations, January 2014 in “World journal of clinical cases” Neomycin is a common cause of follicular contact dermatitis, which is treated by avoiding the allergen and using creams.