CLINICAL ASPECTS ACTA MEDICA TRANSILVANICA June;25(2):18-21 DOI: 10.2478/amtsb-2020-0021 Online ISSN 2285-7079 MYIASIS – PATHOLOGY OR TREATMENT? GABRIELA MARIANA IANCU1, LILIA MAHU2, MARIA ROTARU3 1,3“Lucian Blaga” University of Sibiu, 2County Clinical Emergency Hospital, Sibiu Keywords: myiasis, Abstract: Myiasis is the infestation of live vertebrates with arthropod larvae of the order Diptera. The ulcers, treatment increase in the number of tourists in endemic areas, with the appearance of new cases in risk-free geographical areas, has increased the interest of doctors in knowing the insects that cause myiasis. The most common cases of myiasis are found in tropical and subtropical areas, the temperate zone being of interest in the warm season. In dermatological practice, there are cases of skin myiasis, especially at the level of skin ulcers. The appearance of ulcers myiasis is favoured by the poor socio- economic status, poor hygiene conditions or associated debilitating general pathologies. Performing a correct treatment of ulcers is the main factor in preventing the larval infestation of ulcers. INTRODUCTION Accidental parasite (pseudomyiasis) - can affect the Myiasis, a term derived from Greek (mya = to fly), host by accidental contact (can infest the host by represents the infestation of live vertebrates with arthropod ingestion, migration into the urethra, rectum, vagina, larvae of the order Diptera. This term was proposed by Hope in etc.).(3) 1840 and highlights the difference from larval infestation by Obligate parasites destroy the healthy infested tissues, other insects.(1) invade deep tissues, superinfect the host. Facultative parasites The order Diptera has about 150,000 species of do not destroy healthy tissues, clean the necrotic tissue, produce insects, distributed on all continents. These, with a few antibacterial substances and stimulate granulation. exceptions (Mycetophilidae, Tipulidae, Phoridae and The upward trend in the number of tourists in areas Hippoboscidae), have wings and are active fliers. In the larval with epidemic risk has increased the global interest in knowing stage, they do not have real legs, but they do have a locomotor the insects that cause myiasis, this being classified as the 5th system, which differs depending on the species, having the dermatological disease among tourists. appearance of worms.(2) The triggers for the appearance of myiasis in ulcers The order Diptera is divided into 2 suborders: are: Nematocera (includes most families of blood-eating insects - it - poor socio-economic condition, infects the host with viruses, protozoa, helminths) and - unsatisfactory hygiene, Brachycera (includes the infraorder Muscomorpha which - old age, contains all the species that cause myiasis). - associated pathologies (psychiatric, alcoholism, diabetes), Ulcers myiasis is the infestation of ulcers of various - physical disabilities that restrict care, etiologies with larvae of the order Diptera. The most common - certain climatic conditions (heat, humidity), natural species of flies that ovipositate ulcers are: Cochliomyia disasters, hominivorax, Chrysomya bezziana and Wohlfahrtia magnifica. - rural environment (contact with domestic animals). Zumpt made an anatomical classification of the Favourable conditions for larval development are myiasis, namely: related to excess heat and humidity, thus, larval infestation has - sanguinivorous, an increased incidence in tropical and subtropical areas, in - cutaneous - which may be furuncular or migratory, temperate areas with a seasonal variation.(3,4) A very important - myiasis of ulcerations, role is played by veterinarians in the recognition and treatment - cavitary myiasis (cerebral, sinonasal, otic, ophthalmic, of myiasis in domestic or pet animals, as they are a possible etc.).(3) source of larvae that can be transmitted to humans.(5) - From an ecological point of view, in myiasis, parasites can Performing a correct treatment of ulcers with be: antiseptic solutions, sterile dressings changed periodically Specific/ obligate parasite - depends on the host to allows the prevention of larval infestation. The treatment of survive, ulcerative myiasis consists of irrigation to eliminate larvae, Semispecific/ facultative parasite: primary, secondary, debridement, local application of disinfectants and antibiotic tertiary - can affect the host when it is or is not treatments in case of bacterial superinfection. Despite a infested by other parasites or when it is with a general favourable prognosis, the mental impact on the patient and even condition affected, on the medical staff is extremely important.(3) 1Corresponding author: Gabriela Iancu, B-dul. C. Coposu, Nr. 2-4, Sibiu, România, E-mail: [email protected], Phone: +40744 372164 Article received on 11.04.2020 and accepted for publication on 28.05.2020 AMT, vol. 25, no. 2, 2020, p. 18 CLINICAL ASPECTS CASE REPORTS The treatment consisted in the mechanical removal of We present two clinical cases that were diagnosed and the larvae, compressed with antiseptic solutions (3% borax treated in the Dermatovenerology Ward of the Clinical County solution). After 2 days the destruction of the larvae was obtained Emergency Hospital of Sibiu in the summer of 2019. Elderly then the daily dressing of the ulcerations with epithelializing patients, aged 70 years and 74 years, respectively, known with ointments was performed. florid venous ulcers, presented to the emergency department, afterwards, being referred to our clinic for the presence of larvae DISCUSSIONS at the level of chronic ulcerations. Some dermatological conditions can be associated The risk factors identified in our patients were: with myiasis according to data from the literature, namely: - old age, ulcers (venous, neuropathic, arterial, lymphatic etc.), psoriasis, - the precarious social condition with the lack of domicile seborrheic keratosis, onychomycosis, B-cell skin lymphoma, and of the persons to take care of them, basal cell carcinoma, Shingles, pediculosis, genital warts, - inadequate hygiene and improper care of ulcers, impetigo etc.(3) - physical disability, In dermatological practice, the most common forms of - addiction to tobacco and alcohol, myiasis are the furuncular and cutaneous migratory ones. - favourable climatic conditions (summer) for larval In the furuncular myiasis, Dermatobia hominis and infestation. Cordylobia anthrophaga (present in tropical America) cause At admission, the patients had multiple live yellow, skin-like lesions, most commonly, furuncular-like. Other clinical spindle-shaped larvae, which came out and entered the ulcer bed variants of this form are: vesicular, bullous, pustular, erosive, (figures no. 1,2). ecchymotic or ulcerative form. Upon contact of the larva with As a general pathology, patients presented with the intact skin of the exposed areas, it penetrates it and forms an venous pathology (chronic venous insufficiency stage CEAP 6, erythematous-edematous lesion, hardened, 1-2 cm in diameter, (obliterating arteriopathy of the lower limbs), respiratory with a central microulceration, covered with crusts with purulent pathology (chronic obstructive pulmonary disease), cardiac or bloody appearance, intensely itchy and painful (especially at pathology (permanent atrial fibrillation with medium AV, night). In association, it may have local lymphadenopathy, dilated cardiomyopathy with moderate/ severe systolic fever, altered general condition, insomnia, sensation of dysfunction, chronic NYHA IV, grade II mitral regurgitation) movement at the site of contact. Without intervention, the larva and insulin-dependent type II diabetes. will come to the surface in a few days to a few weeks to turn into a pupae or an abscess will form, causing its death. Figure no. 1. Myiasis of venous ulcers in the first case The differential diagnosis of furuncular myiasis includes insect bites, prurigo lesions, inflamed cysts, pyodermitis, cellulite. The anamnesis and the clinical examination are in the vast majority of cases sufficient to establish a positive diagnosis. In atypical cases, dermatoscopy or ultrasonography are useful tools in diagnosing furuncular myiasis.(6) Dermatoscopically, the presence of D. hominis larva is described as a yellowish structure with black barb-like spines cantered by a microulceration and surrounded by small dilated blood vessels.(3) Ultrasonography is useful in atypical cases for diagnosing furuncular myiasis and for complete extraction of the larva. The furuncular myiasis with D. hominis is described as a well-defined echogenic zone, surrounded by a hypoechoic zone, with segmentations in the longitudinal sections and posterior acoustic shadow.(3) From a therapeutic point of view, furunculoid myiasis can benefit from surgical treatments - extraction of the larva Figure no. 2. Myiasis of venous ulcers in the second case with tweezers, application of dressings or occlusive substances (vaseline, plaster) that asphyxiate or cause the larvae to migrate to the surface, then their manual extraction. If the occlusion treatment is chosen, it must be maintained for at least 24 hours. In this situation, there is a risk that the larva instead of coming to the surface, will suffocate subcutaneously and cause a local inflammatory response. Local injection of lidocaine 1%, and application of ivermectin 1% are other therapeutic variants that immobilize the larvae and allow their extraction. Surgical treatment is rarely chosen, but in some cases it is required for extraction or perilesional debridement.