Chapter 1. Laboratory Studies
Laboratory studies have limited utility in diagnosing atopic dermatitis, but may be helpful in select cases. Patients with atopic dermatitis may have elevated serum immunoglobulin E (IgE) levels. This finding is not specific to atopic dermatitis though and may be seen with a variety of other disorders including asthma, allergies and the hyperimmunoglobulin E syndrome. Up to 20% of atopic dermatitis patients will have a normal serum IgE level, therefore a negative result does not rule-out a diagnosis of atopic dermatitis. Conversely, an elevated IgE level lends support to the diagnosis. Allergy testing may have a role in a subset of patients with atopic dermatitis.