Sir,

In August 2020, a 30-year-old Moroccan patient residing in a village in the town of Taounate, presented with an erythematous and pruritic lesion of the anteo-internal surface of the left thigh which appeared 2 days after handling the wood. Clinical examination revealed an erythematous serpiginous track extending cranially from an erythematous maculopapular lesion with a central vesicle (Fig. 1a). after having eliminated the other differential diagnosis including erysipelas with lymphangitis, erythema migrans due to Lyme disease and cutaneous larva migrans. We retained the diagnosis of Pyemotes ventricosus dermatitis. the patient was put on topical corticosteroid therapy and oral antihistamine, the lesions slowly disappeared (Fig. 1b).

Figure 1: (a) A maculopapular lesion with linear track extending cranially along the arm. (b) The control after 7days.

Pyemotes ventricosus dermatitis is caused by the bite of a free-living ectoparasites P. ventricosus parasitizing the larvae of a wood beetle ‘’Anobium punctatum’’. Humans can be incidental hosts when carrying wood [1]. A specific criterion for Pyemotes ventricosus dermatitis is a serpiginous erythematous track called ‘’comet tail’’ and can roll out other skin reactions to other bites anthropods. The comet tail is due to the transepidermal migration of ectoparasites [2]. It may be assimilated to the onset of lymphangitis. It has to been distinguished from lymphangitis which is characterized by erythematous, irregular, linear streaks extending from the primary site toward the draining regional nodes [3]. In our patient, the comet tail extended cranially to his elbow and not to a site of lymphatic drainage. Systemic symptoms such as fever, chills, vomiting, or intense headache have been reported in some observations [2].

To the best of our knowledge, this is the second case of Pyemotes dermatitis from Morocco [3].

REFERENCES

1. Neumayr A, Kuenzli E. Pyemotes ventricosus Dermatitis:A Serpiginous Skin Lesion due to a Mite that Parasitizes a Wood-Boring Beetle. Am J Trop Med Hyg. 2019;100:1041-2.

2. Sánchez-Bernal J, Aldea-Manrique B, Ramírez-Lluch M, Álvarez-Salafranca M, Ara-Martín M. Pyemotes ventricosus Dermatitis:Comet-Shaped Skin Lesions after Contact with Woodworm-Infested Furniture. Skinmed. 2020;18:305-6.

3. Tomczyk-Socha M, Jedrzejewska-Jurga K, Limburska J, Tomczyk J. Outbreak of Occupational Dermatitis Associated With Pyemotes ventricosus. JAMA Dermatol. 2017;153:686-8.