**Question:** Boxer's ear is -

A. Erythema marginatum
B. Erythema elevatum diutinum
C. Erythema marginatum nodosum
D. Erythema elevatum diutinum with mucosal involvement

**Core Concept:** Boxer's ear is a clinical manifestation seen in different dermatological disorders, often associated with chronic urticaria and systemic lupus erythematosus (SLE). It is characterized by the presence of reddish-colored papules on the ears, typically seen in patients with chronic urticaria or SLE.

**Why the Correct Answer is Right:**
Correct Answer: D. Erythema elevatum diutinum with mucosal involvement

Erythema elevatum diutinum with mucosal involvement (EED) is a subtype of Erythema elevatum diutinum (EED), which is a subtype of chronic urticarial vasculitis. This specific subtype is characterized by the involvement of mucosal surfaces, including the oral, nasal, and genital mucosae. In this case, the correct answer (D) is chosen because it includes mucosal involvement, which is a distinctive feature of EED.

**Why Each Wrong Option is Incorrect:**

A. Erythema marginatum: This is a distinct entity characterized by a targetoid, sharply demarcated, red-brown papulovesicular rash, usually found on the limbs. It is not associated with mucosal involvement.

B. Erythema elevatum diutinum: Erythema elevatum diutinum is a cutaneous vasculitis characterized by the presence of red-brown papules on the extremities. It is not associated with mucosal involvement, making it incorrect.

C. Erythema marginatum nodosum: Erythema marginatum nodosum is a subtype of Erythema marginatum involving the subcutaneous tissue, resulting in nodular lesions. It is not associated with mucosal involvement, making it incorrect.

D. Erythema elevatum diutinum with mucosal involvement: As mentioned earlier, this subtype includes mucosal involvement, making it the correct answer.

**Clinical Pearls:**

Boxer's ear is a clinical manifestation that occurs in patients with chronic urticarial vasculitis, specifically Erythema elevatum diutinum with mucosal involvement. This condition is characterized by the presence of reddish-brown papules on the extremities and mucous membranes, which may include the ears, lips, and oral mucosa. The condition is associated with autoimmune disorders, particularly systemic lupus erythematosus and rheumatoid arthritis. The involvement of mucous membranes and skin lesions on the extremities is crucial in identifying the correct answer.