A 56-year-old white woman with poorly controlled type 2 diabetes presented with unilateral periorbital angioedema. Topical steroid ointment and oral antihistamines were ineffective. After skipping her two-week follow-up appointment, the patient returned six months later when the rash became bilateral. As at the previous visit, there was a bright red rash that occasionally oozed serous discharge from the involved skin (sparing the orbits and globe). She was not taking an ACE inhibitor or angiotensin receptor blocker and reported no use of substances that might cause contact dermatitis. What could this be? To what type of specialist should she be referred—ophthalmology, dermatology, or allergy?
—TERESA NOVAK, PA-C, Lincoln, Neb.

Angioedema presents as an abrupt, nonpitting, flesh-colored, or erythematous swelling of skin, mucous membranes, or both. In addition to lax areas of skin, the respiratory and GI tracts may be involved. Angioedema may occur in the presence or absence of urticaria. Allergic angioedema is an immunoglobin E-mediated immediate hypersensitivity reaction associated with the release of histamine or other mediators from mast cells; it has various causes, including medications (e.g., nonsteroidal anti-inflammatory drugs, antibiotics, and ACE inhibitors), environmental contacts, foods (i.e., seafood), and insect venoms. Angioedema usually occurs within one to two hours after exposure to the responsible allergen and is more common in people with atopy (allergic rhinitis, asthma, and/or atopic dermatitis). Hereditary, drug-induced, idiopathic, and mixed forms of bradykinin-induced endothelial activation can mediate angioedema. In addition, angioedema can be idiopathic (acute or chronic), associated with contact or physical urticaria, secondary to a defect in the plasma inhibitor of the first component of complement (C1-INH deficiency) that is either hereditary or acquired, or associated with urticarial vasculitis. The last two possibilities have been observed in patients with systemic lupus erythematosus or other systemic diseases (Clin Dev Immunol. 2007;2007:26438). In addition to an allergist, dermatologist, or ophthalmologist, the woman with periorbital angioedema and accompanying eczematous changes might benefit from evaluation by a family practitioner, internist, or rheumatologist.
—Philip R. Cohen, MD