High prevalence of parasitic infections in chronic spontaneous urticaria: Evidence for a potential pathogenic link

Chronic spontaneous urticaria (CSU) is a dermatologic condition characterized by recurrent, pruritic hives lasting more than 6 weeks. Although usually associated with autoimmune or allergic mechanisms, recent studies suggest that parasitic infections may contribute to the pathogenesis of CSU.

This study aimed to investigate the prevalence of parasitic infections in CSU patients and to examine their potential associations.

A total of 99 CSU patients and 30 controls were evaluated for parasitic infections by stool and serologic testing. In addition to wet mount microscopy, zinc sulfate flotation, formol-ether concentration, cellophane tape method, trichrome and modified Kinyoun acid-fast staining methods were applied to enhance the detection of parasites. Furthermore, enzyme-linked immunosorbent assay was conducted to detect Entamoeba histolytica antigen in stool and Toxoplasma gondii and Taenia spp. antibodies in serum.

A significantly higher rate of parasitic infection was found in the adult CSU group (52.5%) compared to the control group (30%; P = 0.033). The difference in total parasite presence between the urticaria and control groups was significant. T. gondii, G. intestinalis, and Blastocystis sp. were more common among urticaria patients. T. trichiura and Cryptosporidium were detected only in the urticaria group.

The findings suggest that protozoans, particularly Blastocystis sp. may play a role in exacerbating CSU. Further studies are needed to elucidate the specific mechanisms by which parasites influence CSU pathogenesis and to explore the potential for targeted antiparasitic therapies.