Chief Complaint: “I woke up with painful blisters on my arm.”

History of Present Illness:
A 29-year-old male farmer presents to the clinic with a sudden onset of burning, redness, and blister formation on his right forearm. The symptoms started in the morning, shortly after waking up. He recalls working late on his farm the previous evening and leaving his shirt outside before wearing it again that night. He denies insect bites or scratching before the blisters appeared.

Upon further questioning, he mentions seeing a long, dark-colored beetle on his bed when he woke up, but he brushed it off without concern. The pain and irritation increased throughout the day, and new fluid-filled blisters appeared along a streak-like pattern on his arm.

Physical Examination:

• Well-demarcated, linear erythematous patches with large, fluid-filled blisters on the right forearm
• No pus, ulceration, or signs of secondary infection
• No fever, swollen lymph nodes, or systemic symptoms

Diagnosis:
Based on the history and characteristic skin findings, the patient is diagnosed with vesicating beetle dermatitis (blister beetle exposure), caused by cantharidin, a toxin released by certain beetles when crushed against the skin.

Management Plan:

• Supportive care: Cool compresses and topical petroleum jelly to soothe the affected skin
• Medications: Topical corticosteroids and oral antihistamines for pain and itching
• Wound care: Avoid popping blisters to prevent secondary infection; keep the area clean and dry
• Patient education:
  • Be cautious when handling or crushing beetles
  • Shake out clothing before wearing it
  • Keep sleeping areas free of beetles, especially in rural or farming regions

The patient is reassured that the condition is self-limiting and should resolve in about a week without scarring. A follow-up visit is scheduled to monitor healing.