Patients with papular urticaria have IgG antibodies to bedbug (Cimex lectularius) antigens.

IgG and IgE against salivary gland proteins of bedbug (Cimex lectularius) were assessed in comparison with mosquito (Culex pipiens) and flea (Pulex irritans) antigens in the sera of papular urticaria patients (group I), siblings without papular urticaria (group IIa), patients' parents (group IIb), and healthy controls (group III) (Immunoblotting). Anti-C. lectularius IgG was significantly recognized at 66 and 10 kDa in 40% of group I, besides others ranging from 45 to 107 kDa. Group IIa significantly reacted with 70 kDa (57.1%). Group IIb reacted with 21 and 8.5 kDa (26.7%). Sixty percent of group IIb and 100% of group III significantly identified a band of 12.5 kDa. IgG against C. pipiens was significantly recognized at a range of 18-105 kDa in group I, IIb (115, 7 kDa), and III (58, 50 kDa). Anti-P. irritans IgG was significantly recognized by group I (100, 70 kDa) and group IIa (60, 35 kDa). IgE response was confined to C. pipiens at 115 and 54 kDa in groups I and III, respectively, besides 68 and 58 kDa in group IIa. It is concluded that IgG is present against C. lectularius, C. pipiens, and P. irritans in papular urticaria and may contribute to its pathogenesis.