Allergic Contact Dermatitis from Poison Ivy in a 49-Year-Old Male Patient Presentation
A 49-year-old male presented to our dermatology clinic in Katy, Texas, with a one-week history of a red, itchy rash on the right leg, groin, and left arm. The rash developed after spending time doing yard work, and the patient suspected possible contact with poison ivy. The rash was described as moderate in severity and had not improved with any over-the-counter treatments.
Clinical Examination
A focused dermatologic examination was performed, including inspection of the face, arms, legs, and genital area. The patient declined a full-body skin exam.
On examination, there were well-demarcated, geometric, eczematous patches distributed across the left arm, penis, and right leg, consistent with allergic contact dermatitis. No evidence of secondary infection or vesiculation was noted.
The patient was well-developed, well-nourished, alert, and oriented, and appeared in no acute distress. A dermatoscope was utilized during the evaluation for lesion assessment.
Diagnosis
Allergic Contact Dermatitis (L23.9) – secondary to likely exposure to poison ivy during yard work.
Treatment Plan
After confirming the clinical impression, the patient was counseled regarding appropriate skin care and environmental precautions to prevent recurrence.
Medications:
Prednisone 20 mg tablets – Tapering course:
Take 2 tablets (40 mg) once daily for 5 days
Then 1 tablet (20 mg) once daily for 5 days
Then 1 tablet (20 mg) every other day for 10 days
Total: 20 tablets
Counseling and Recommendations:
Skin Care:
Use gentle, fragrance-free, hypoallergenic cleansers.
Avoid scented soaps, detergents, and personal care products.
Apply fragrance-free moisturizers to support skin healing.
Environmental Precautions:
Avoid further exposure to poison ivy and wash all clothing or gear that may have contacted plant oils.
Clean tools and pets that may have come into contact with contaminated vegetation.
Prednisone Counseling:
The patient was counseled extensively on the risks and precautions associated with systemic corticosteroid use, including:
Short-term effects: increased appetite, mood changes, insomnia.
Long-term risks (with extended use): weight gain, osteoporosis, high blood pressure, and glucose elevation.
The patient verbalized full understanding of the tapering schedule and potential adverse effects.
Follow-up Plan:
Follow up as needed (PRN) if the rash fails to improve or recurs.
Consider patch testing in the future if recurrent or chronic allergic dermatitis is suspected.
Discussion
Allergic contact dermatitis (ACD) is a common inflammatory skin reaction caused by exposure to allergens such as poison ivy, nickel, fragrances, or topical products. The characteristic linear or geometric patterns are often diagnostic clues.
Poison ivy dermatitis results from contact with urushiol, an oil that triggers a delayed-type hypersensitivity reaction. Prompt washing with soap and water after exposure can minimize severity.
In moderate to severe cases involving widespread areas or sensitive regions like the genitalia, a prednisone taper is often required to control inflammation and prevent rebound flares.
At Village Dermatology in Katy and Houston, Texas, Dr. Reena Jogi and her team specialize in diagnosing and treating allergic skin conditions with tailored medical therapy, environmental guidance, and patient education.
Conclusion
This case illustrates a classic presentation of allergic contact dermatitis secondary to poison ivy exposure, successfully managed with a prednisone taper and detailed counseling on allergen avoidance and gentle skincare practices. With proper care, the patient’s rash is expected to resolve completely within several weeks.
