TINEA UNGUIUM.

later report, one of us (Cheeseman, 1950) reported no cases in five girls' schools examined and attack rates varying from 2.61 to 10.39 per cent. per term in 11 boys' schools. Age Incidence.-The ages of the patients in the present series ranged from 11 to 60 years. According to the Medical Research Council (1938) most authorities agree that tinea cruris is seldom seen before puberty, but little information is available about relative risks at varying ages of adult life. Mode of Spread.-It is assumed that infection may be spread via underclothing, athletic straps, sportswear, etc., but in practice this theory is seldom substantiated. It may be that infection may be spread via the fingers, since the groin area is a most favourable site for fungus infection due to the frequency of excessive perspiration, and the fingers themselves are not infected. Other infections undoubtedly result from simple spread of infection from toes, nails, etc., to the groin. Treatment.-Again, there are many efficient fungicides, any one of which suffices, and the important points regarding prevention of reinfection from clothing, elimination of other affected areas, such as toes and nails, are all important. Prevention.-Personal hygiene would appear to be the most important single factor in the prevention of tinea cruris, and the general preventive measures applicable to tinea pedis apply. It is of interest to note that the attack rates in boarding schools where patients were isolated were generally much less than those in schools where isolation was not practised (Medical Research Council, 1938; Cheeseman, 1950). Differential Diagnosis of Tinea Cruris.-The important differential diagnosis is seborrhceic intertrigo. This condition is always bilateral and is usually quite symmetrical. In addition, it frequently spreads on to the perianal region. There is little margination, and other manifestations of seborrhceic dermatitis may be found elsewhere.