Patients with psoriasis often have increased serum levels of IgA antibodies to gliadin.

It was recently observed that in six patients with psoriasis and one with palmoplantar pustulosis, with newly discovered gluten intolerance, a gluten-free diet had a remarkable effect on the skin lesions. This prompted us to undertake a screening investigation to discover whether increased levels of serum antibodies to gliadin are more common in patients with psoriasis than in healthy persons. IgA and IgG antibodies to gliadin (IgA AGA and IgG AGA) were quantified by a micro-ELISA method. Out of 302 patients with psoriasis, 16% (18 females, 31 males) showed serum IgA AGA levels above the 90th percentile value (51 u/ml) of the reference group. This tendency was even more marked when the proportion of patients with values > 70 u/ml was compared with the corresponding proportion of 99 reference subjects. Thus, 3% of the reference subjects but 7.9% of the patients had values > 70 u/ml. The corresponding figures for men were 1.6% and 8.9%, respectively. Men with psoriasis had a significantly higher mean IgA AGA than the male reference group. The means based on logarithmic values of the individual IgA AGA values were significantly higher in the psoriatic groups than in the reference groups. Although the mean level of IgG AGA was not increased in the psoriasis group, there was a correlation between the values for IgA AGA and IgG AGA. The serum concentrations of IgG, IgA and IgM were also measured. In the male patients, the mean IgA value was significantly increased. Women in whom IgA AGA was elevated also showed a significantly increased mean IgA.(ABSTRACT TRUNCATED AT 250 WORDS)