**Question:** All are vesiculo bullous lesions except-

A. Impetigo
B. Urticaria
C. Erythema multiforme
D. Drug reaction with eosinophilia and systemic symptoms (DRESS)

**Correct Answer:** B. Urticaria

**Core Concept:** Vesiculobullous lesions are skin lesions characterized by the formation of vesicles (small, fluid-filled blisters) and bullae (large, ruptured blisters). These lesions can be caused by various underlying conditions or medications.

**Why the Correct Answer is Right:** Urticaria is a type of skin reaction characterized by the formation of raised, red, and itchy wheals (wheals). It is not a vesiculobullous lesion, making option B correct.

**Why Each Wrong Option is Incorrect:**

A. Impetigo: Impetigo is a bacterial infection caused by Staphylococcus aureus and Streptococcus pyogenes. It presents as superficial, purulent, and crusting lesions and is not a vesiculobullous lesion.

C. Erythema multiforme: Erythema multiforme is a group of skin reactions characterized by target-like lesions and mucosal involvement. It is not a vesiculobullous lesion, making option C incorrect.

D. Drug reaction with eosinophilia and systemic symptoms (DRESS): DRESS is a drug reaction characterized by fever, lymphadenopathy, and systemic involvement. It presents with generalized skin rash and mucosal involvement. DRESS is not a vesiculobullous lesion, making option D incorrect.

**Clinical Pearl:** Understanding the clinical features and pathophysiology of various skin lesions is crucial for a medical student or resident to diagnose and manage patients effectively. It helps in differentiating between various skin disorders and selecting the appropriate treatment.