We made this treatment decision with the knowledge that such doses might produce adverse effects, including an increase in appetite, fluid accumulation, irritability, and sleeplessness. Before prescribing these medications, the potential effects were thoroughly discussed with the patient and a history was taken to rule out antecedent diabetes, severe hypertension, intercurrent infection, peptic ulcer disease, or bipolar affective disorder, all of which could be worsened by the use of corticosteroids.
So-called “dosepaks” of corticosteroids are far too weak for such a serious condition, and topical medications—even the most powerful—will be of little benefit. I gave Patient 2 one more thing: a prescription for hydroxyzine hydrochloride (25 mg tablets, to be taken at bedtime), both for sedative and antipruritic effects. For milder cases of poison ivy, I often advise no treatment except topical because the one thing that can be depended on is that poison ivy will resolve on its own, eventually.
I also educate patients about the appearance of the poison ivy plant (see Figure 3). In my part of the country (Oklahoma), where poison ivy is found in virtually every fence line, every creek bank, and every backyard, most people don’t really know what it looks like. Part of that confusion results from the fact that it can take a number of forms, including a vine, often wrapped around trees, a small tree, or even a root, coursing along the ground. Its distinguishing features include the “leaves of three” in typical shapes (darts, with notches, or “thumbs” along the leaf margins), a shiny surface, and white flowers turning into berries.
TAKE-AWAY LEARNING POINTS
• Poison ivy is predominantly found east of the Rocky Mountains and poison oak almost exclusively to the west of them. Poison sumac is limited to the southeastern United States.
• Poison ivy is also known as a form of phytodermatitis, with other botanical sources such as ficus, fig, fern, mango, rhus, and Japanese lacquer trees.
• Poison ivy can grow in the form of a bush, a vine, or even a small tree. However, it also demonstrates the “leaves of three.”
• Linear blisters on an erythematous base is the classic description of a poison ivy reaction, but it can also present in a more diffuse form that concentrates on the popliteal areas and medial thighs.
• Poison ivy is not “poison.” It is the quintessential contact dermatitis, a type IV delayed hypersensitivity reaction to the oil contained in the plant.
• Poison ivy is not contagious and cannot be spread on the patient’s body or to anyone else.