The patient (male, age 85 years) seen in Figure 3 presented with a facial “rash.” Palpation and examination revealed erythema, dryness, scaling, and thickening of the skin on the forehead, nose, cheeks, and chin. KOH test for Demodex mites was negative; however, clinical appearance and symptoms strongly suggested the possibility of Demodex infestation. The patient was treated with topical crotamiton twice daily, instructed to use a moisturizer, and returned four weeks later for a follow-up visit. The patient showed marked improvement in the central third of the face and was instructed to continue crotamiton application twice daily. A second follow-up visit four weeks later showed marked reduction in erythema, with no evidence of erythema detected on the forehead, nose, cheeks, and chin. Crotamiton application was decreased to once daily at bedtime.
This is caused by inflammation and infiltration of the blood vessel wall as an anaphylactic reaction to a number of physical and chemical stimuli, including infections. Henoch-Schönlein purpura (HSP) is one of the most common. It is often preceded by an upper respiratory tract infection due to beta-haemolytic streptococcal infection. It can occur in epidemics in young children with a fever followed by a purpuric rash which may be slightly raised. Typically, it affects the fronts of the legs and the buttocks. There may be associated acute arthritis, gastrointestinal pain and nephritis with proteinuria. The rash may continue to form over several weeks. Serious acute complications include central nervous system (CNS) bleeding, acute intussusception or acute kidney injury. Usually it is a self-limiting condition but it may respond to steroids. A Cochrane review found no evidence of benefit of short courses of prednisolone in preventing serious kidney disease in HSP. [ 9 ]
Demodex folliculorum is a saprophytic mite of the human pilosebaceous unit with a prelidiction for facial skin and eyelashes. Infestation occurs frequently without symptoms; however, suppurative or granulomatous inflammation may be seen with high mite density. Skin lesions, such as rosacea, pityriasis, and blepharitis, have been attributed to Demodex; however, its role in sebaceous adenoma (SA) has not been reported in extensively searched medical literature. We report this rare case and review the skin lesions associated with Demodex folliculorum .