Allergy testing can aid the diagnosis of allergic disorders; however, it is not diagnostic. With skin testing, in particular, a positive result does not necessarily indicate clinical allergy, and a negative result does not always exclude clinical relevance.
The mother of an 11-month-old boy was concerned by a constellation of symptoms including mild fever and rhinorrhea of several day’s duration, lesions that resembled insect bites on one leg and acute swelling of one foot. Early-stage Henoch-Schnlein purpura was suspected. What is your impression?