What is causing episodes of pruritic facial erythema?

My patient is a woman in her late 30s who has several episodes a month of confluent facial erythema that is very warm to the touch and highly pruritic. The episodes resolve without treatment. There is no xerodermatitis or evidence of systemic lupus erythematosus. She has no systemic symptoms. Her blood pressure is normal, and all laboratory and urinalysis results are normal.

What might be causing her facial erythema? How is it treated?

—— MD

Given this limited description, 2 things come to mind. First, consider the differential diagnosis. Although the clinical findings in this patient are compatible with rosacea, do not overlook carcinoid, mastocytosis, mitral valve incompetence, or cutaneous lupus, all of which are possible causes. Rarer causes include medullary carcinoma of the thyroid, pancreatic cell tumor, and renal carcinoma.

Second, if you suspect rosacea in a patient with pruritus, keep in mind that Demodex mites, as well as foods that trigger histamine release, may be to blame. Crotamiton has been reported to be effective for ameliorating both the rosacea and the itching.¹

Flushing is probably one of the most difficult aspects of rosacea to control. It is important to investigate the temporal relationship between flushing episodes and any previous exacerbating factors. In addition to the better-known factors (heat, cold, wind, sunlight, stress, exercise, hot or cold foods, spicy foods), there can be other triggers. Some have linked rosacea outbreaks to foods high in histamine or niacin (eg, cheese, yogurt, citrus fruits, liver, chocolate, vanilla, soy sauce, vinegar, eggplant, avocados, spinach). I have found occult sinus infection or sinus allergy to be an exacerbating cause. I would also recommend investigation for a possible hormonal connection.

If conventional treatments for rosacea are not effective, β-blockers have been reported anecdotally to work for some patients.¹