ORIGINAL ARTICLE Dermatitis caused by arthropods in domestic environment: an Italian multicentre study L. Stingeni, 1, * L. Bianchi, 1 K. Hansel, 1 D. Neve, 1 C. Foti, 2 M. Corazza, 3 V. Bini, 4 I. Moretta, 5 M. Principato 5 1 Section of Clinical, Allergological and Venereological Dermatology, Department of Medicine, University of Perugia, Perugia, Italy 2 Section of Dermatology, Department of Biomedical Science and Human Oncology, University of Bari, Bari, Italy 3 Section of Dermatology, Department of Medical Sciences, University of Ferrara, Ferrara, Italy 4 Internal Medicine, Endocrine and Metabolic Sciences Section, Department of Medicine, University of Perugia, Perugia, Italy 5 Department of Veterinary Medicine, University of Perugia, Perugia, Italy *Correspondence: L. Stingeni. E-mail: luca.stingeni@unipg.it Abstract Background Skin diseases caused by mites and insects living in domestic environments have been rarely systemati- cally studied. Objectives To study patients with dermatitis induced by arthropods in domestic environment describing their clinical features, isolating culprit arthropods and relating the clinical features to the parasitological data. Methods The study was performed in 105 subjects with clinical and anamnestic data compatible with the differential diagnosis of ectoparasitoses in domestic environments. Clinical data and arthropods findings obtained by indoor dust direct examination were studied. Results Indoor dust direct examination demonstrated possible arthropods infestation in 98 subjects (93.3%), more fre- quently mites (56.1%) (mainly Pyemotes ventricosus and Glycyphagus domesticus) than insects (43.9%) (mainly Formici- dae and Bethylidae). Strophulus (46.9%) and urticaria-like eruption (36.7%) in upper limbs and trunk with severe extent were prevalent. Itch was mostly severe (66.3%) and continuous (55.1%). Ectoparasitoses occurred frequently with acute course in summer (44.9%) and spring (30.6%). Conclusions Possible correlation between clinical and aetiological diagnosis of arthropods ectoparasitoses in domes- tic environments needs the close cooperation between dermatologist and parasitologist. This is crucial to successfully and definitely resolve skin lesions by eradicating the factors favouring infestation. Received: 2 March 2017; Accepted: 12 June 2017 Conflicts of Interest None declared. Funding Sources None declared. Introduction Dermatitis induced by arthropods in domestic environments is an increasing health problem in industrialized countries. Never- theless, systematic studies on skin diseases caused by mites and insects living in indoor environments have been rarely reported, 1–3 and only several single case reports of skin injuries induced by a large variety of different arthropods were described. 4–11 The presence of arthropods in indoor environments is condi- tioned by microclimatic factors and by arthropod reservoirs, such as moulds on walls, plants, pets and worm-eaten wooden structures (furniture, parquet, beams, firewood). Moreover, reproductive cycle of several indoor arthropods is seasonally conditioned and their seasonal peaks increase risk of morbidity for humans. 12,13 Excluding lice and scabies mite, numerous indoor arthropods can determine a great variety of skin lesions. The most frequent clinical picture is papular urticaria, characterized by small ery- thematous, urticarial papules capped by a tiny vesicle or with a central haemorrhagic punctum. 4,7,8 We prefer to name this clini- cal picture ‘strophulus’ (from ancient Greek rsqό/ος: ‘turn of bowels’ 14 ) instead of papular urticaria, which is frequently used to indicate skin diseases with different aetiologic and patho- genetic mechanisms. 15 Other clinical features frequently reported are erythematous and excoriated papules, urticaria- and scabies-like lesions, erythematous papules and pustules. 5,6 © 2017 European Academy of Dermatology and Venereology JEADV 2017 DOI: 10.1111/jdv.14438 JEADV