A 3-year-old child presents with red, itchy patches on his cheeks, forehead, and scalp, and has a history of asthma. The lesions are characterized by vesicles and crusting. What is the most likely diagnosis? A) Chickenpox B) Atopic dermatitis C) Impetigo D) Hand, foot, and mouth disease E) Contact dermatitis Correct Answer: A) Chickenpox Explanation: Chickenpox (varicella) presents with itchy vesicles on an erythematous base, which eventually crust over. The lesions appear at different stages of development, and it often starts on the face and scalp. Atopic dermatitis (B) often presents with eczema on flexural areas, but it is not associated with vesicles or crusting. Impetigo (C) is a bacterial infection that causes honey-colored crusting, but it usually involves the mouth or nose, not widespread on the cheeks or scalp. Hand, foot, and mouth disease (D) presents with vesicular lesions on the hands, feet, and oral mucosa, not on the cheeks and scalp. Contact dermatitis (E) causes itchy, erythematous lesions due to an allergen or irritant but does not lead to vesicle formation and crusting. Key Tips for PLAB 1: ✅ Vesicular rash = Chickenpox ✅ Crusting lesions = Classic sign of chickenpox healing ✅ Management = Antihistamines for itching, calamine lotion, and supportive care
