Delayed complications of sulfur mustard poisoning in the skin and the immune system of Iranian veterans 16-20 years after exposure

Background Extensive cutaneous burns caused by alkylating chemical warfare agent sulfur mustard (SM) have been associated with the severe suppression of the immune system in humans. We aimed to study the association between late cutaneous and immunological complications of SM poisoning. Methods Skin examination was performed on all SM-poisoned Iranian veterans in the province of Khorasan, Iran, who had significant clinical complications, and their SM intoxication was confirmed by toxicological analysis. Light microscopy was performed on eight skin biopsies. Blood cell counts, serum immunoglobulin and complement factor, as well as flow cytometric, analyses were performed on all the patients. The severity of cutaneous complications were classified into four grades and compared with hematological and immunological parameters, using Spearman's rank correlation test. Results Forty male subjects, confirmed with SM poisoning 16-20 years earlier, were studied. The main objective findings were hyperpigmentation (55%), dry skin (40%), multiple cherry angiomas (37.5%), atrophy (27.5%), and hypopigmentation (25%). Histopathologic findings were nonspecific and compatible with hyperpigmented old atrophic scars. Except for the hematocrit and C4 levels, hematological and immunological parameters revealed no significant correlation with the severity grades of cutaneous complications. Conclusion Sulfur mustard is an alkylating agent with prolonged adverse effects on both the skin and the immune system. Allthough skin is a major transporting system for SM's systemic absorption, there is probably no correlation between the severity of late cutaneous and immunological complications of SM poisoning.