Mycetoma is reported in both males and females of all age groups but some groups are affected most. It occurred more frequently in the young adult males, with ages ranging from 15-30 years, but no age is exempted specially in endemic areas. Patients at this age grouprepresent the most active and the earning members of the society, particularly in developing societies where the life expectancy is short.
Not all occupations are equally encountered in the patient population. Most of the mycetoma patients appear to earn their living by working on the land, peasant and herdsmen and the farmers are affected more often. However, in a recent study, 30% of reported patients appeared to be young students. This may due to the fact that, mycetoma is commonly seen in this age group, increased educational facilities in the endemic areas and the children commonly share the various outdoor activities with their families. In endemic areas, other professionals such as workers, clerks and health workers may also be affected.
In all previous reports, male predominance is a constant finding in mycetoma. In general, the gender ratio in eumycetoma is (3:1) which is higher than that encountered in actinomycetoma (2.7:1) and the explanation of this is unclear. The male predominance is commonly attributed to the greater risk of exposure to organisms in the soil during the outdoor activities. However, in areas where mycetoma is prevalent in the Sudan, both sexes go barefooted and in Western Sudan women are more committed to outdoor activities than males and yet the incidence of the disease is the same as that observed in other parts of the country. These findings are in line with reports from Kenya, Congo and others.
It may be that women are inherently less susceptible to infection with mycetoma due to differences in sex hormone levels, but this seems not to be the case. Women have much higher levels of 17 -estradiol than man, but in male mycetoma patients higher 17 -estradiol levels were reported than in non-infected males. However, it is interesting to note, during pregnancy the mycetoma lesions become more aggressive, active with formation of new discharging sinuses, (Personal observation), and the depressed immunity during pregnancy may partially explain this observation, however, other causes must be considered.
Another difference between men and women which could be of influence in developing mycetoma is the make-up of the skin. Men have a thicker dermal compartment of the skin, less subcutaneous fat, have a higher basal blood flow in the skin, generate more sebum and sweat, have larger pores in their skin and most importantly have a slower wound healing. All these differences can be important in a subcutaneous infection.
In general, mycetoma patients are considered to have a normal functioning immune system, although there are some reports, which showed partial impairment of the cell-mediated immune (CMI) response in patients severely infected or not responding to medical treatment. This finding was supported by animal studies, since mycetoma was more successfully induced in athymic mice than in immunocompetent mice. In another report, some impairment in the innate immune response was noted. Overall, still no convincing evidence exists that showed mycetoma patients have particular immune defects