An association with thyroid disease in some patients has been described but is controversial. No racial variance in prevalence exists. Peak incidence is in the second and third decades. Whealing usually develops within 5 minutes of stroking the skin and persists for 15-30 minutes. A refractory period after the wheal has cleared has been reported and often is short.
Giant wheals can develop when a deep extension of the swelling occurs.
A minority of patients develops symptomatic dermographism, in which itching is disproportionately severe compared to the whealing and often is most severe at night. One patient was reported in the literature with dyspareunia and vulvodynia resulting from symptomatic dermographism. A possible association with seborrheic dermatitis exists. Occasionally, this condition is associated with cholinergic urticaria. This form is recalcitrant to conventional therapy and is related closely to pressure urticaria.