**Question:** Ulcer on the penis which bleeds on touch is feature that best in which of the following –

A. Venereal disease
B. Infective dermatitis
C. Lichen sclerosus
D. Eczema

**Correct Answer:** .

**Core Concept:**
The description provided revolves around a penile ulcer that bleeds upon touch, which could signify an underlying pathology. Penile ulcers can be caused by various conditions, each with distinct clinical features and treatment approaches. In this case, the symptomatology matches closely with one of the options provided.

**Why the Correct Answer is Right:**
The correct answer, **C. Lichen sclerosus**, is chosen due to the following reasons:

1. Lichen sclerosus is a chronic, autoimmune disorder affecting both men and women, which primarily affects the genitalia.
2. It presents with white, atrophic, tender, and painful plaques, often ulcerating, and bleeding on touch, similar to the described ulcer on the penis that bleeds on touch.
3. Lichen sclerosus is characterized by the involvement of the penile skin, urethral meatus, and sometimes the vulva in women.

**Why Each Wrong Option is Incorrect:**
A. Venereal disease (e.g., syphilis) typically presents with a variety of symptoms, including genital ulcers, which may be non-tender or painful, not specifically characterized by bleeding upon touch.
B. Infective dermatitis presents with inflammatory skin lesions, generally non-ulcerated or with superficial ulcers, not exhibiting the described bleeding upon touch.
D. Eczema is an allergic reaction affecting the skin, often itching, and not typically characterized by bleeding upon touch.

**Clinical Pearl:**
Lichen sclerosus is a clinically significant entity, especially in cases presenting with atrophic, tender, and painful plaques, often ulcerating and bleeding upon touch. This condition is a reason for careful differential diagnosis in patients presenting with genital ulcers, as it has implications for treatment approach and prognosis. Early diagnosis and referral to an appropriate specialist (e.g., dermatologist or urologist) are essential to manage the condition effectively.