A demodicosis case which responded to systemic ivermectin

ARTICLE

Auteur(s) : Yelda Karincaoglu¹, Ozlem Miman², Bulent Kalayci¹, Ozlem Makbule Aycan², Metin Atambay²

¹Inonu University School of Medicine, Department of Dermatology and Venerelogy, 44315 Malatya - Turkey
²Department of Parasitology, Faculty of Medicine, Inonu University, Malatya - Turkey

Demodex folliculorum (DF) is the most common ectoparasite of the pilosebaceous unit [1]. We present a case of demodicosis which had an atypical clinical manifestation at different localizations and which was treated with systemic ivermectin.

A 36-year-old male patient presented at the dermatology clinic complaining of acneiform lesions on the face, hairy skin and ear auricles, and scale on the nasolabial folds and eyelashes for about 5 months. The patient, who did not have a photosensitivity history, had marked itching in the lesions. These complaints had been interpreted as acne vulgaris and seborrheic dermatitis and the patient had been prescribed various topical and systemic antibiotics from different groups, as well as topical steroids at irregular intervals, and had used antibiotic eye drops and ointments for his blepharitis. However, the patient had no benefit from these treatments and reported occasional exacerbations of his lesions. His dermatological examination showed many erythematous, slightly bright, non-squamous acneiform papulopustules with a diameter of 4 to 6 mm, which were located on the scalp, earlobes and cheeks. There were also erythematous, mildly squamous and inflammatory bilateral blepharitis signs, which were more marked on lower eyelids (figure 1). The patient, who did not have classical acne vulgaris, rosacea or seborrheic dermatitis, was suspected clinically of having demodicosis and a DF examination was performed. Samples collected from the forehead, cheek, nose, chin and ear using standard surface skin biopsy showed 28, 18, 10, 15 and 15 DF per cm², respectively and samples collected from the eyelashes by depilation methods revealed 8-10 DF in a single follicle. The patient was prescribed 5% permethrin topical cream twice a day, and 4% pilocarpine gel once daily for blepharitis. After two weeks of treatment, the patient’s blepharitis recovered completely clinically, while his face lesions were unresponsive. Consequently, the patient was administered a single-dose oral 200-250 μg/kg ivermectin. One month after ivermectin administration, an almost complete remission was observed in the lesions.

The classically involved areas are those with high sebum production, like the forehead, cheek, nose, nasolabial folds, chin and eyelids [1]. Our patient had hairy skin involvement, which has previously been shown to be a rare localization, and auricle involvement, which is unique in the literature. The parasite has been shown in the external ear cerumen [2], but has never been described as an auricle lesion. Recently there have been reports of atypical demodicosis cases [3, 4]. Agents used to eradicate infestations with demodex mites include topical metranidazole, permethrin, lindane, sulfur, crotamiton, retinoids, selenium sulfide, salicylic acid and benzyl benzoate [1]. In the treatment of resistant or diffuse lesions, systemic treatments like metranidazole, retinoids and ivermectin may be preferred [1, 5]. Routine use of 5% permethrin cream twice a day for 15 days is reported to produce satisfactory results. In some cases, this treatment is continued for one month in combination with 2% salicylic acid cream [3].

Our case was initially treated with topical permethrin, but due to irritation and the extensiveness of the lesions, systemic ivermectin treatment was started. Use of 4% pilocarpine gel in blepharitis of demodex origin has been reported to eliminate symptoms and statistically significantly reduce the number of mites before and after treatment [6]. Our case also responded very well to topical pilocarpine for blepharitis. We think that pilocarpine is a good alternative for chronic blepharitis associated with demodicosis, and systemic ivermectin for diffuse facial lesions unresponsive to topical treatments.

Acknowledgements

References

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