Jack, an 83-year-old nursing home resident, has increasing redness around the anus and natal cleft, noted by nursing staff who request his GP to review. The staff report that the area is tender on palpation, there is no associated discharge, but focal small, spotted, dark discolorations are noted. Jack has intermittent incontinence of urine and faecal incontinence, with a previous history of recurrent groin and peri­anal fungal rash that was successfully treated with topical clotrimazole/hydrocortisone 1% cream. Jack also has a past history of atrial fibrillation, GORD, osteoarthritis, constipation, non-insulin-dependent diabetes and diverticulitis.  

On review, the GP notes an area of well- demarcated erythema around the natal cleft of approximately 8 x 3cm diameter (figure 1).