A case of atopic dermatitis caused by Ascaris lumbricoides infection.

BACKGROUND: Parasite infections stimulate total and specific IgE production that, in the case of Toxocara canis infection, corresponds to chronic allergic symptoms. There may also be other infections which have similar symptoms, such as Ascaris lumbricoides infection. Ascaris lumbricoides is a large nematode that causes abdominal pain, nausea, vomiting, bloating, anorexia and intermittent diarrhoea. Patients with ascaridiasis and high IgE levels may also have allergy-like symptoms such as asthma, urticaria and atopic dermatitis. CASE PRESENTATION: We report a case of atopic dermatitis caused by Ascaris lumbricoides which shows the important role of parasitic infection in patients with long-lasting dermatitis. The patient was a 12-year old female suffering since early infancy from atopic dermatitis and asthma. She was treated for dermatitis with oral bethametasone and topical pimecrolimus with little benefit. After two cycles of mebendazole therapy, the patient showed progressive improvement of symptoms. CONCLUSIONS: In patients with dermatitis, Ascaris lumbricoides infection should be not excluded: adequate anthelmintic treatment may result in complete regression from the disease.

A case of apparent contact dermatitis caused by Toxocara infection.

Infection from Toxocara species may give rise to a large array of clinical symptoms, including apparent manifestations of allergy such as asthma, urticaria/angioedema, and dermatitis. We report a case, thus far not described, of contact dermatitis attributed to nickel allergy but caused by Toxocara infection. The patient was a 53-year-old woman presenting from 10 years a dermatitis affecting head, neck, and thorax. Patch tests initially performed gave a positive result to nickel, but avoidance of contact with nickel did not result in recovery. The patient referred to our Allergy Service in 2010 because of dermatitis to feet. Patch testing confirmed the positive result for nickel, but expanding the investigation a positive result for IgG antibodies to Toxocara was detected by Western blotting and ELISA. Treatment with mebendazole achieved immediate efficacy on feet dermatitis. Then, two courses of treatment with albendazole resulted in complete regression of dermatitis accompanied by development of negative ELISA and Western blotting for Toxocara antibodies. This report adds another misleading presentation of Toxocara infection as apparent contact dermatitis caused by nickel and suggests bearing in mind, in cases of contact dermatitis not responding to avoidance of the responsible hapten and to medical treatment, the possible causative role of Toxocara.

Seroprevalence of IgG anti-Toxocara species antibodies in a population of patients with suspected allergy.

BACKGROUND: Toxocara canis is an intestinal nematode affecting dogs and cats, which causes human infection when embryonated eggs excreted in dog feces are ingested. Humans are paratenic hosts. Although the larvae do not develop into adult worms in the human body, they may migrate to various tissues and organs where they can survive for several years, giving rise to several clinical symptoms, which can present in allergy-like form. METHODS: Over 5 years, we examined 9985 patients referred for suspected allergies, based on symptoms such as dermatitis, urticaria, rhinitis, asthma, and conjunctivitis; 753 patients who had allergy tests negative or unrelated to clinical history were tested for seropositivity to T. canis by enzyme-linked immunosorbent assay (ELISA) or Western blotting (WB). RESULTS: In 240 patients (31.8%), ELISA or WB or both tests were positive for T. canis immunoglobulin G (IgG) antibodies: in particular, 64 of them (26.7%) were positive to ELISA, 110 (45.8%) to WB, and 66 (27.5%) to both tests. Asthma was the most common clinical presentation. Two thirds of patients underwent subsequent anthelmintic therapy and showed a complete remission of symptoms and, in 43% of patients retested by ELISA and WB, became negative to Toxocara. CONCLUSION: These findings strongly suggest that T. canis plays a significant role in inducing chronic symptoms presenting as suspected allergies.

Safety of hymenoptera venom immunotherapy: a systematic review.

INTRODUCTION: The efficacy of venom immunotherapy (VIT) in patients with insect sting allergy is not questioned. However, its safety, especially when honeybee is used, is a matter of concern. AREAS COVERED: A systematic review of the literature on VIT was done, with both aqueous and depot extracts, to compare the frequency of systemic reactions to honeybee and vespid venoms. A Medline search was performed using the keywords 'venom immunotherapy', 'safety' and 'tolerability'. The articles obtained were analyzed regarding the total number of patients treated with either honeybee or vespid VIT, the number and severity of systemic reactions during therapy, the type of extract used (aqueous or depot) and the administration regimen. EXPERT OPINION: The incidence of systemic reactions to VIT was 25.1% for honeybee venom and 5.8% for vespid venom (p < 0.0001), while it was similar with aqueous and depot extracts in the whole population of patients. This confirms that during VIT systemic reactions are significantly more frequent with honeybee venom compared with vespid venom, while there are no significant overall differences in systemic reactions between aqueous and depot extracts.

Toxocariasis resulting in seeming allergy.

Toxocara canis is an intestinal nematode affecting dogs and cats that causes human infestations by ingestion of embryonated eggs excreted in dogs' faeces. Humans are transport hosts, in whom the larvae do not develop to adult worms, but may migrate to various tissues and organs, and survive for several years, giving rise to several clinical symptoms, which include allergy-like presentations. We report three cases presenting as dermatitis, rhinitis, asthma, and conjunctivitis which were diagnosed and unsuccessfully treated as allergy. The correct diagnosis was established after detecting anti-Toxocara antibodies by Western blotting. All clinical symptoms showed improvement after starting treatment with mebendazole and subsequent courses of the antiparasitic drug resulted in full recovery. This suggests the possible role of Toxocara canis in inducing chronic symptoms of allergic type. This is particularly important for asthma, where it has been demonstrated that Toxocara canis infection causes allergic inflammation in the lungs associated with bronchial hyperreactivity. On the other hand, in our patients with asthma and with dermatitis the positive results from allergy tests were a confounding factor in delaying the correct diagnosis, which was finally obtained by the detection of antibodies to Toxocara canis.