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Avian mite infestation is a rare cause of pruritic dermatoses in humans. The mites spend the majority of their life cycle on the avian host but may be transmitted to man as a result of direct contact and also through airborne spread. We describe a case of infestation with the Northern Fowl Mite (Ornithonyssus sylviarum) from an abandoned birds nest in the roof of a patients home. This caused a pruritic erythematous papular eruption on exposed sites that settled with topical steroids. We discuss the diagnosis and range of clinical manifestations produced by avian mites.

During late summer in 1995 to 1997, repeated outbreaks of maculopapular skin eruptions were noted on the legs of children after wading in the pond in the Family Park in Laugardalur, Reykjavík, Iceland. Clinical symptoms developing on the legs resembled those of cercarial dermatitis. An examination of Lymnaea peregra snails from this pond and from the adjacent Lake Tjornin resulted in detection of previously undescribed schistosome cercariae. This is the first report of schistosomes in Iceland and also the most northern occurrence of these parasites in Europe.

A one-year-old male, chequered giant rabbit had a simultaneous infestation with both Leporacarus gibbus and Spilopsyllus cuniculi. Recurrent episodes of mild to severe pruritus had been noted over a period of two months. On clinical examination, partial alopecia and slightly erythematous skin with flea faeces was evident, although microscopic and cultural examinations of skin scrapings were negative for fungi. Parasitological examination, including adhesive tape strips of the rabbit's skin and fur, revealed L gibbus surface dwelling mites and the rabbit flea S cuniculi. The rabbit was successfully treated against both parasites with topical pyrethrin applied three times over a three-week period, and the clinical signs resolved in four weeks.

A 9-year old German Shepherd bitch was presented with a recent onset of seborrhoea oleosa, hyperpigmentation, erythema, pruritus and alopecia along the neck, thorax, ventrum and the dorsal area of the carpus. The skin changes were believed to be caused by Dirofilaria immitis infection. A combination of topical and parenteral anti-heartworm therapy led to the resolution of the lesions.

Sowda skin lesions are of medical and social importance in Yemen. Ivermectin (Mectizan) chose as a control strategy plan in onchocerciasis is active during 3 months for the less on clinical and histological data. After a short increase of itching and oedematous skin aspects clinical signs decrease. Some patients notice an itching rebound after 90 days. Histologically, localized ingratiates, presence of mononuclear cells and melenin loaded histiocytes and eosinophils decreased. The rythm cure has to be studied on a longer period but 3 to 6 months repetition between oral treatment with 200 micrograms/kg dose during two years could be effective.

Chromosome characteristics of Trichobilharzia franki Müller et Kimming, 1994, causing swimmer's itch in the Western Germany, were described and compared with the karyotype of the sympatric species Trichobilharzia szidali Neuhaus, 1952. Karyotypes of both species are very similar: diploid sets consist of seven pairs of autosome chromosomes and one pair of sex chromosomes (2n = 16, n = 5m + 2sm + Zsm/Wst), the sex determining mechanism is ZZ in males and ZW in females and gross morphology of autosome pairs does not differ markedly. The only clear discriminative feature lies in the size and shape of sex chromosomes.

In three women with persistent pruritus, aged 49, 28 and 4 years, infestation with the bird or chicken mite (Dermanyssus gallinae) was demonstrated. These mites live in narrow openings and cracks close to the bird housing during the daytime. At night they attack the birds on whose blood they live. When their host disappears, they may attack men, notably when their breeding places are in or near houses. Mite bites result in urticarial and itchy papulovesicular skin eruptions. Treatment of bird mite infestation consists of removing the old nests. Treatment of the patients is symptomatic. Epizoonosis belongs in the differential diagnosis of pruritus; infestation with bird or chicken mites is one of the possibilities.

An investigation of human infection with Onchocerca volvulus and the resulting clinical disease was carried out for the Nigerian National Onchocerciasis Control Programme between July and August 1989 [corrected]. The survey covered 10.6% of the rural population in 41 savanna villages of central Nigeria. Of the 8451 self-selected individuals examined, 900 (10.6%) had skin microfilariae (Mf). There were differences between villages in both endemicity and intensity of infection, but in general the number of both Mf carriers and cases of clinical onchocerciasis increased with age. The disease in the Mf carriers showed as blindness (0.8%), onchocercal nodules (0.6%), leopard skin (1.6%) and pruritus (2.8%). Of 35 persons with lymphatic complications, 19 had hanging groin, 10 had elephantiasis and six had hydrocoele. Onchocerciasis was mesoendemic in the rocky northern escarpments, and became hypoendemic and sporadic in the southern uplands of sedimentary geological origin.

In the course of an onchocerciasis survey in southern Malawi, body weight was recorded for 10,335 persons aged 20 years and older, and the body mass index was calculated for 5572. A history of symptomatic complaints was elicited from 5653 persons 20 years of age and older. Persons with microfilariae in the skin snips weighed significantly less than persons with negative skin snips. Symptomatic complaints of musculoskeletal pains, itching, dizziness and poor vision were reported more commonly in the group with microfilariae. These findings suggest that onchocerciasis should no longer be considered a disease affecting the eye and skin only but an infection which produces systemic effects as well. Systemic effects of onchocerciasis may lessen productivity of an endemic region by a process distinct from the effects of visual impairment.

The association between papular skin lesions in slaughtered pigs and hypersensitivity to Sarcoptes scabiei var suis was examined in experimental and field studies, and by the retrospective analysis of monitoring records obtained at slaughter. A causal role for S scabiei was indicated by the production of lesions in experimentally infested pigs, by increased clinical mange in herds having high lesion scores, and by a reduction in the severity of lesions after the implementation of more intensive mange control measures. The specificity of the lesions as an indicator of sarcoptic mite hypersensitivity was estimated to be 0.92 from experimental data and 0.79 from field data. Generalised lesions were rare in mange free pigs, indicating that such lesions were highly specific (1.0 from experimental data, greater than 0.98 from field data) for mange. The assessment of the severity of the lesions in samples of slaughtered pigs appears to be a useful aid to assessing the severity of sarcoptic mange in pig herds.

This article attempts to cover the more specific pruritic problems encountered in rabbits, rodents, and ferrets. There are certainly other causes of pruritus in these animals. Dermatophytes in guinea pigs are not reported to be pruritic, but because they are pruritic in other species, they should be considered in a differential diagnosis. A cryptococcal dermatitis in a guinea pig that was pruritic has been reported. Although mites were not seen on scraping, the animal was treated for sarcoptid mites and apparently the pruritus lessened. Because the cryptococcis was still present, it is questionable whether it was causing the pruritus. Pruritic ulcerative dermatitis over the back and shoulders has been seen in some lines of rats. Staphylococcus aureus was cultured from many of the lesions. Clipping the toenails on the feet helped lessen the severity of the lesions. Syphacia spp. have been reported in rats, gerbils, and hamsters and should be considered if there is perineal pruritus. MOBS, or "move over buddy syndrome," is seen especially in mice and may be seen in hamsters, gerbils, and rats that are overcrowded or stressed. The lesions are actually bite wounds that have been inflicted around the tail base and the perineum and on the tail, but these wounds can be mistaken for self-inflicted trauma from pruritus. All of the recommended treatments are extralabel, and clients should be informed of this. I have observed a guinea pig become lethargic and anorexic after only one application of a flea powder approved for use in cats. Brushing most of the powder off and offering dandelion greens to stimulate appetite helped. The second dusting was done with the same flea powder diluted with baby powder. Whenever these animals are dipped, it is important to let them dry in a warm, draft-free area. Again, it is important to be aware that the ratio of surface area to body weight is much higher in these small animals than in the species routinely seen in veterinary practice especially to prevent toxicoses from topically applied medications and iatrogenic hypothermia or hyperthermia.

Twenty-three species of Culicoides were trapped near pruritic horses during a 2-year survey in Florida. Nearly 99% of the biting midges collected were represented by Culicoides insignis Lutz, C. edeni Wirth and Blandon, C. stellifer (Coquillett), C. niger Root and Hoffman, C. haematopotus Malloch and C. venustus Hoffman. The relative contribution to the total catch by each of these species varied among collection sites. Seasonally, different species attain their largest population sizes at different times. Association of species collected in light traps with the seasonality of lesion development on the horses suggests that more than one species must be involved in causing Culicoides hypersensitivity in horses from Florida. Nulliparous females were present in most months that females of the same species were active; in some cases, species were trapped in each month of the year, particularly at the more southerly sites. The species of biting midge most likely to be involved in Culicoides hypersensitivity in horses in Florida are C. insignis, C. stellifer and C. venustus based upon their mammalophilic behaviour and seasonality.

With the recent influx of southeast Asians into the United States, an increased incidence of human gnathostomiasis can be expected. A Laotian woman had had two weeks of pruritus associated with fleeting erythematous patches on her abdomen. A peripheral eosinophilia was present. She withdrew a Gnathostoma spinigerum from the skin of her abdomen. Gnathostomiasis is endemic in much of Asia and causes not only migratory cutaneous swellings with erythema but also serious visceral sequelae such as eosinophilic encephalomyelitis. Excision of the parasite is the treatment of choice when possible.

Flea allergy dermatitis is one of the most common causes of pruritus in dogs and cats. The degree of pruritus observed in the allergic animal varies widely and is dependent on numerous factors. Management of the flea-allergic patient is extremely frustrating for the owner and the veterinarian. Establishing an organized flea control program for use on the patient and in the environment will help to avoid frustration when dealing with this common ectoparasite of cats and dogs.

A survey of sweet itch in horses in Israel based on a questionnaire to owners reported that 158 of 723 horses (21.8 per cent) had sweet itch lesions. The results indicated that the likelihood of a horse acquiring sweet itch decreased with increasing altitude but no definite association with rainfall zones was evident. Variation in the density of the horse population, however, obscured these observations. In the population surveyed, stallions were more sensitive than mares and pale horses appeared to be less sensitive than dark ones, but the sample size of this latter group was much smaller. Intradermal injection of extracts of Culicoides imicola and Stomoxys calcitrans gave immediate reactions in sensitive horses but delayed reactions were observed only with extracts of C imicola. Sensitivity to extracts of C circumscriptus was also evident in allergic horses. Antibodies to extracts of Culicoides species and Stomoxys species were demonstrable in the serum of normal and allergic horses by the ELISA technique.

Cheyletiellosis and scabies can cause pruritus in dogs and cats. Cheyletiellosis is variably pruritic, whereas scabies is usually intensely pruritic. Hypersensitivity reactions are described in both of these parasitic dermatoses and probably contribute to the development of lesions and pruritus. Both parasites are readily eradicated with insecticides.

Norwegian scabies is an ectoparasitic infestation by Sarcoptes scabiei, characterized by hyperkeratotic lesions of the hands, feet, ears, and scalp, which contain many mites. An epidemic of Norwegian scabies involved 22 patients in a 25-patient ward of mentally and physically handicapped persons (mostly mongoloids). The pathogenesis of the prolific mite population is unclear, but either a specific immunologic deficit or the inability to effectively eliminate the mites by scratching is a plausible possibility.