Co‐reactivation of the human herpesvirus alpha subfamily (herpes simplex virus‐1 and varicella zoster virus) in a critically ill patient with COVID‐19

namely 10% and 34%, respectively in 1988, compared with 5% and 28% (if seborrhoea is included) or 18% (for eczema excluding seborrhoea). 8The differences might indicate a lower threshold for referral or an actual increase in disease prevalence.The apparent surge in impetigo and tinea in the first quarter of the twentieth century, as judged by Radcliffe Crocker's hospital data and the 1921-22 Edinburgh figures, in comparison with McCall Anderson's 1873 observations, is possibly from close contact of school children. 5,6 It is notable that Radcliffe Crocker's 1903 private patients had lower prevalences of infections and infestations, suggesting a social class difference. 6 By the mid-twentieth century, effective treatments had largely conquered such contagions irrespectively of social class.The biggest surprise for the present-day dermatologist must be the very low rate of skin cancers of any description in the 1920s, something that was still apparent in 1950s Northern Ireland. 7 Accepting the evidence that skin cancer incidence increased in the last quarter of the twentieth century, an additional explanation for the low prevalence of skin cancers may be that in the 1920s presentations were delayed and, because life expectancies, as mentioned, were lower, those affected may have died from other causes before their cutaneous malignancies precipitated referral.An additional possibility, impossible to quantify, is that some or indeed most skin cancers, such as basal cell carcinoma, were referred directly to surgeons.A major criticism of this and other clinic-based case mix studies is one of selection referral, something that can only be overcome by true population studies, of which there are very few for skin disease.A recent such study by Svensson et al. of 12 377 participants aged 18-74 years, drawn from Germany, Italy, the Netherlands, Portugal and Sweden, showed that, for 'active manifestation' (rather than lifetime prevalence), eczema was the most common diagnosis, at a point prevalence of 16% (most frequently, contact dermatitis), with psoriasis at 3%, acne 5%, vitiligo 1Á4% and skin cancer 0Á5%. 9he study by Svensson et al. suffers from the drawback that it excludes children and those older than 74 years, thus skewing the findings away from atopic dermatitis and skin cancers.No similar population study exists for the early part of the twentieth century to indicate whether the 1921-22 data are applicable to the populace at large.However, some inference might be drawn by looking at the ranking of diseases.In 1921-22 data, tinea, impetigo and scabies were the second, third and fourth most common diagnoses (accounting for 39% of referrals), implying significant prevalence in the public at large, whereas for Svensson et al. these conditions did not merit their own diagnostic categories. 9he dermatological case mix of a century ago at the founding of the British Association of Dermatologists shows both similarities and differences from that of the present day.A wide range of factors, including environmental, social, medical referral practice and demographic, seem to be involved in the observed shifting pattern of case mix.