Which of the following is the most common side effect of Isotretinoin used for acne vulgaris?: (A) Facial erythema, (B) Xerosis, (C) Hair loss, (D) Cheilitis
Answer is D. Cheilitis is the most common side effect of isotretinoin. Ref: Rook Textbook of Dermatology, 8th edition, Page 42.64