Question

A 45 year old male has multiple grouped vesicular lesions present on the T10 segment dermatome associated with pain. The most likely diagnosis is:

• A. Herpes zoster
• B. Dermatitis herpetiformis
• C. Herpes simplex
• D. Scabies

Hint:

One nerve strip, grouped vesicles, and pain together point to shingles.

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
A 45 year old man has grouped vesicles confined to the T10 dermatome, along with pain in that area. We need to pick the diagnosis that fits a single dermatome distribution with pain.

Step 2: Key Formula or Approach:
The strongest clue in this question is the word dermatome. A dermatome is the strip of skin supplied by a single spinal nerve root, and only one common skin disease follows this exact strip pattern with associated nerve pain: reactivation of a nerve residing virus.

Step 3: Detailed Explanation:
Dermatitis Herpetiformis causes grouped itchy vesicles but favors extensor surfaces like elbows and knees on both sides of the body, not a single nerve strip, and it is not painful in the way described here. Herpes simplex causes grouped vesicles too, usually around the mouth or genitals, in a localized patch rather than following a nerve root strip across the trunk. Scabies causes itchy papules in finger webs and genital skin, spread by contact, and does not follow a dermatome or cause the sharp pain described.
Herpes zoster, commonly called shingles, happens when the chickenpox virus, which stays dormant in a nerve root ganglion after a person's first infection, reactivates later in life. It travels down that one nerve and produces grouped vesicles on a red base strictly limited to the skin area supplied by that nerve, here the T10 dermatome, which wraps around the trunk at roughly the level of the umbilicus. The pain, often burning or stabbing, typically comes before or along with the rash, because the virus irritates the nerve itself.

Step 4: Final Answer:
The most likely diagnosis is herpes zoster, because the lesions are grouped, painful, and strictly limited to one nerve root, the T10 dermatome.