Painful grouped vesicles on an erythematous base.

• A. Varicella
• B. Herpes Zoster
• C. Eczema
• D. Herpes Simplex

Answer: (D)

Painful grouped vesicles on an erythematous base are classic for herpes simplex infection of the skin or mucosa. The vesicles occur in tight clusters on a reddened patch and are typically painful, often around the lips or genital area. This pattern reflects HSV reactivation at a local site and helps distinguish it from other vesicular rashes.

Varicella (chickenpox) typically shows vesicles in crops at various stages scattered across the body and is usually very pruritic, not just a single clustered group. Herpes zoster (shingles) also has grouped vesicles, but they follow a dermatomal distribution, are usually unilateral, and are extremely painful along a nerve tract. Eczema (atopic dermatitis) centers on inflamed, itchy skin and can have vesiculation in acute flares, but the classic description of grouped vesicles on an erythematous base points to herpes simplex.