DiGeorge syndrome presenting with palmoplantar pustules: Comparative analysis of serum IL-22, NETs and IL-8 with usual palmoplantar pustulosis.

DiGeorge syndrome, also known as 22q11.2 deletion syndrome, shows cellular immunodeficiency due to by thymic hypoplasia and hypocalcemia caused by hypoparathyroidism. It was reported that erythrodermic psoriasis occurred in a patient with 22q11 deletion syndrome. Here, we report the first case of DiGeorge syndrome presenting with a severe palmoplantar pustulosis (PPP)-like eruption with extra-palmoplantar lesions on the distal limbs. Given that PPP is a subtype of pustular psoriasis, the pustular eruption may be associated with DiGeorge syndrome. We measured serum levels of citrullinated histone H3 (CitH3), a representative marker of neutrophil extracellular traps, interleukin (IL)-8, and IL-22 and compared them with nine cases of typical PPP. In the PPP patients, the three markers were higher than in healthy subjects with significant correlations between CitH3 and IL-8/IL-22. In our patient, CitH3, IL-8, and IL-22 were also high, and IL-22 was remarkably elevated compared with the PPP patients. Our case suggests that a certain T cell abnormality associated with DiGeorge syndrome induces IL-22 overproduction, leading to the PPP-like eruption with extra- palmoplantar lesions.