A patient presents with a rash. In emergency medicine we often recognize certain rashes at a glance, like urticaria or a viral exanthem. This does not fit any of those. The patient is scratching vigorously. Is this atopic dermatitis, commonly known as eczema?
Eczema might be the most common rash we see in the emergency department but its presentations are diverse so it is not always a “know it at a glance” diagnosis. We can get tricked. The etymology of eczema is “out boiling.” which describes that rash that is papulovesicular with erythema and weeping and crusting. A lot of rashes do that of course.
Atopic dermatitis is a special disease that arises from a defect in the epithelial connections between cells. When you understand that, you can diagnose it, and you can treat it.
The epithelial defect leads to microscopic “holes” in the skin. Water gets out, and irritants get in. Itching is dramatic.
Here is how you diagnose atopic dermatitis in the emergency department:
-Pruritus is a must
-The classic inflammatory rash of eczema (papulovesicular with erythema and weeping)
Allow for hyperkeratosis if the lesions are subacute or chronic
Allow for findings of excoriation
So far that hasn’t nailed down the specificity yet. Any inflammatory rash will do all that. Poison oak, for example will do the same thing.
Add in the specificity with:
–dry skin by history or current presentation (defect in skin barrier)
–distribution is flexural or hands by history or current presentation (areas of trauma and friction)
-history of atopic diseases or childhood onset
Now that you have the diagnosis, it is all about restoring hydration, and restoring the skin barrier. Have them take baths, hydrate the skin, and then lock it in with ointment. Teaching that will empower them to be less reliant on steroids.
TAKE HOME POINTS
-Suspect atopic dermatitis by severe itching and an inflammatory rash
-Localizes to areas of friction (hands or flexural areas)
-Dry skin prominent
-History of allergies or asthma
-Usually childhood onset