Case: Dermatology #1
Case Study: Dermatology Cases for Primary Care
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“I’m so itchy I can’t stand it! I have this burning, itchy rash that kept me up most of the night scratching.”
Case #1: Susan is a 49-year-old female who comes into the office complaining of a very itchy rash on her arms, legs, and chest following a weekend of raking and burning brush in her yard. She self-treated with calamine lotion but was not satisfied with the response and comes in this morning to be treated for the rash and itching.
Patient has lived in New England all her life. Her hobbies include working in her yard, cooking, and reading. She denies taking any new medication since the onset of symptoms. No exposure to new soaps or detergents. No pets.
Past medical history is unremarkable for any known food, medication, or environmental allergies. She vaguely recalls being exposed to poison ivy as a child.
Physical Examination
Weight 135 lbs, BP 126/76, P 81
HEENT: No facial or periorbital edema. No difficulty breathing or speaking.
Cardiac: Regular rate and rhythm, no murmur. Patient reports no dizziness or lightheadedness.
Lungs: Clear to auscultation.
Skin: Back—Clear. Extremities: Extensive linear-type rash with blisters bilaterally.
Chest: Blistered rash above right breast. No weeping, but slight abrasions from scratching.
How would you proceed?
Published on May 11, 2010
Updated on May 17, 2010
Follow-up
Given that Susan was working in her yard immediately preceding the onset of her rash, the most likely diagnosis is contact dermatitis from exposure to poison ivy. Although poison oak can cause the same rash, it is more likely to be found in the western and southern parts of the United States than in New England. The fact that Susan vaguely recalls being exposed to poison ivy as a child is another clue. Her initial exposure would not have produced symptoms; only subsequent exposure results in an allergic response. An additional clue is that Susan had been burning brush from the yard. The rash associated with poison ivy is caused by an oily resin called uroshiol, which is easily vaporized upward by fire. As the resin cools off, it ‘rains’ back downward and can coat any unexposed skin areas.
Susan was instructed to treat the small areas of her rash with topical triamcinolone (Kenalog) and the larger areas with cool compresses of water or aluminum acetate (Burow’s solution). Diphenhydramine (Benadryl) or hydroxyzine (Atarax) 25 mg po q6h will help mild itching between application of compresses. Tepid tub baths with Aveeno colloidal oatmeal (1 cup in 1/2 tub) or cornstarch and baking soda (1 cup of each in 1/2 tub) will also provide soothing relief.
Contact Dermatitis to Sumak (poison oak or ivy)—Treat with topical steroid lotion,anti histamines etc
Large areas of poison ivy or poison oak need at least three weeks of prednisone. A medrol dosepak is not enough. Here in California we have a lot of poison oak, and patients really suffer if only given cortisone creams. (I was the patient given only a medrol dosepak and the rash returned after the second day)