A study on Demodex folliculorum in rosacea.

A random sample of 16 female patients suffering from papulopustular rosacea (PPR) as well as (16) normal female healthy subjects as control group were adopted in this study to assess of Demodex folliculorum pathogenesis. It was done through determination of mite density using a standard skin surface biopsy 10.5 cm2 from different designated 6 areas on the face, and scanning electron microscopic study (SEM) as well as total IgE estimation. A trial of treatment using Crotamiton 10% cream with special program was also attempted. All subjects ranged between 35-55 years old. All patients with rosacea and 15 of the control group i.e. 75.93% were found to harbour mites. The mean mite counts by site distribution were 28.6 & 6.9 on the cheeks, followed by 14.5 & 3.0 on the forehead and lastly 6.8 & 0.8 on the chin in PPR and control groups respectively. The total mean mite count in patients was 49.9 initially and 7.9 after treatment. In the control group it was 10.7 & 10.6 respectively. The mean total IgE was 169.4 & 168.4 and 96.3 & 98.4 in PPR and control groups respectively Light and scanning electron microscopy revealed that all mites were pointing in one direction. Some of them were containing bacteria inside their gut and on their skin. After treatment 3 cases (18.75%) were completely cured, 10 cases (62.5%) gave moderate response while 3 cases (18.75) have no response. In conclusion, this study supports the pathogenic role of D. folliculorum in rosacea.