Mario Antonello Principato

Dermatitis caused by arthropods in domestic environment: an Italian multicentre study

Skin diseases caused by mites and insects living in domestic environments have been rarely systematically studied.

Indoor dermatitis due to Aeroglyphus robustus.

DEAR EDITOR, Aeroglyphus robustus is an astigmatid mite described initially by Banks in 1906 and called Glycyphagus robustus. In 1941 Zachvatkin described and called the subfamily Aeroglyphinae and the genus Aeroglyphus. He considered this mite of Canadian origin to be the same as the European species A. peregrinans (Berlese, 1892), and he upgraded the subfamily Aeroglyphinae to family Aeroglyphidae. It was only in 1959 that Cooreman described A. robustus in detail, distinguishing it morphologically from A. peregrinans. At present, in the Italian acarofauna, A. robustus is not present in the family Aeroglyphidae, and its pathogenic role in humans has never been described before. The taxonomy of A. robustus is order Astigmata, suborder Acaridia, superfamily Glycyphagoidea, family Aeroglyphidae. A 57-year-old nonatopic healthy man was referred for an itchy rash with small and isolated erythematous papules, some with pinhead-shaped central tense vesicles and some excoriated and covered by small crusts. The lesions initially involved the extensor surface of the forearms and the sides of the trunk (Fig. 1); after 1 week they spread to the upper and lower limbs. The patient’s wife showed similar skin lesions. They had no other systemic symptoms, and physical examination was otherwise unremarkable. The patient was a farmer, and 1 5 months earlier he had brought home two large bags of grain, cramming them in at the entrance. The grain, of unknown origin, had been collected from a container located near the patient’s house. The patient and his wife were treated with oral cetirizine (10 mg per day) and desoximetasone ointment, with partial reduction of itching and skin lesions within 10 days. Domestic ectoparasitosis was suspected. In order to verify it, sawdust collected from all of the rooms and the grain bags was examined with E.D.P.A. (Esame Diretto Polveri Ambientali), patented by one of the authors. Briefly, dust samples were collected by broom and dustpan from the floor of the home’s rooms and labelled in small containers. After microsieving, sedimentation or flotation, pathogen arthropods and their specific traces (fragments, exuviae, bristles, faeces) were observed with a stereomicroscope and prepared and mounted on slides in warm Berlese solution for direct observation by optical microscope. The dust sample collected from the grain bags was twice as rich in weeds/pests as those collected from the rooms of the house. However, in both samples A. robustus was identified, with several adults (Fig. 2a) and immature forms (protonymphs, nymphs, larvae). Aeroglyphus robustus is morphologically characterized by dorsally tuberculate idiosoma covered by numerous idiosomal multibranched bristles shaped like wheat plugs and, in particular, by two very long opisthosomal bristles in the female (Fig. 2b). The so-called hypopial deutonymphs of A. robustus were also identified (Fig. 2c); they are typical forms of resistance to untoward environmental conditions. Inspection of the house showed the presence of moulds of the genera Penicillium and Aspergillus, in a high relative humidity (85%), on some north-facing walls. The patient tried to eliminate the house infestation using an aerosol automatic spray insecticide based on cyfluthrin. This approach turned out to be ineffective because the mites hide where the insecticide does not reach them and because of the presence of the resistant form (hypopial deutonymph). In fact, a new E.D.P.A. examination showed vital adults and immature forms of A. robustus. Intervention by a pest-control company was then required and the domestic environment was fumigated with cyphenothrin. Immediately the patients’ skin lesions improved, but after 2 weeks similar new skin lesions in the farmer and his wife appeared again. Probably, hypopial

Arachnidism by Segestria bavarica with severe neuropathic pain successfully treated with lidocaine 5% plaster

Arachnidism by Segestria bavarica with severe neuropathic pain successfully treated with lidocaine 5% plaster Spider poisoning in Europe is rare, and only a few families within the Araneae order are medically relevant. In particular, spiders of dermatological concern mainly belong to Latrodectus and Loxosceles genus. A 45-year-old woman was referred to us with a large erythematous and edematous indurated plaque with well-defined central pallor on the medial aspect of her right forearm. There were consensual lymphangitis and axillary lymphadenitis (Fig. 1a). Systemic symptoms were not present, and laboratory findings were unremarkable. Intense pain radiated from the bite to her arm, with dysesthesia (burning, tingling, numbness, “electric shock like,” pins and needles sensation), hypoesthesia to touch, and allodynia, causing mild disability on daily activities. She reported that 3 days previously, she suddenly woke up at night with acute severe bite-like pain on the site and found a dead spider without one leg lying in her bed sheet. Within 1 day, a little erythematous and edematous area, centered on two close red dots, appeared with local mild pain. A diagnosis of necrotic spider bite with lymphangitis and severe localized neuropathic pain (LNP) was made (11-point Numeric Rating Scale [NRS]: 8; Neuropathic Pain Diagnostic Questionnaire [DN4]: 7). The patient was treated orally (amoxicillin-clavulanic acid, 1 g bid; prednisone, 25 mg qd) and topically (clobetasol propionate ointment, bid) for 1 week. Because of LNP, lidocaine 5% plaster (10 cm 9 14 cm adhesive plaster, containing 700 mg [5% w/w] lidocaine) once a day for up to 12 hours was applied. After 2 weeks, erythema and edema subsided, and central yellowish eschar with well-defined border was present (Fig. 1b). The patient noticed an improvement in pain (NRS: 4; DN4: 6), which was further improved after another 2 weeks of therapy (NRS 3; DN4 3), when only mild tingling, numbness, and hypoesthesia to touch were present. Two months after the spider bite, she had a small depressed and hypopigmented scar (Fig. 1c) with mild hypoesthesia to touch localized to the surrounding skin. The treatment was then discontinued, without recurrence of pain. The spider found by the patient (Fig. 2) was entomologically identified by the Department of Veterinary Medicine of Perugia University, Italy, as Araneae Labidognatha, Segestriidae: Segestria bavarica Kock, 1843. Spiders of the Segestriidae family are widely present in Europe. They mainly live in holes, between and under stones, or under the tree bark, coming out only for hunting, especially during the night in spring and summer. However, in colder climates they can become synanthropic, and they can also be found in cities. Human attacks are mainly due to Segestria florentina Rossi, 1790, while Segestria bavarica is generally harmless, and no case of arachnidism has ever been reported. Segestriidae rarely induce poisoning, with general symptoms like fever, headache, fatigue, and dizziness, normally resolved in about 1 week. Skin lesions, localized in the bite site, are generally erythematous and edematous, without eschars or scarring outcomes. Skin lesions due to Segestriidae are usually painful; burning sensation and hypoesthesia, suggesting LNP as in our patient, were previously described. Segestriidae venom contains neurotoxins responsible for neuropathic pain. The good result obtained with lidocaine 5% plaster is due to a dual mode of action, by providing a mechanical barrier effect and a pharmacological action via voltage-gated sodium channel blockade as a direct result of lidocaine action. This therapy is successfully

Generalized papular-purpuric eruption due to Solenopsis fugax bites

A 59-year-old atopic man referred to for the onset of a diffused itching papular-purpuric eruption involving his trunk and legs but without systemic symptoms. History revealed that he started feeling itching after spending few hours in his basement. Direct examination of the environmental dust (www.edpa.it) showed high level of infestation of Solenopsis fugax, a small Myrmicinae ant. The skin eruption completely healed without scarring in 2 weeks. Specific disinfestation measures were performed and the patient did not comply of any recurrence during a 6-months follow-up.A 59-year-old atopic man referred to for the onset of a diffused itching papular-purpuric eruption involving his trunk and legs but without systemic symptoms. History revealed that he started feeling itching after spending few hours in his basement. Direct examination of the environmental dust (www.edpa.it) showed high level of infestation of Solenopsis fugax, a small Myrmicinae ant. The skin eruption completely healed without scarring in 2 weeks. Specific disinfestation measures were performed and the patient did not comply of any recurrence during a 6-months follow-up.