Caterpillar dermatitis

Outbreak Report of Airborne Caterpillar Dermatitis in a Kindergarten

BACKGROUND

The oak processionary caterpillar is found in several European countries. The larva of Thaumetopoea processionea Lepidoptera from the third to sixth larval instar develops poisonous hair (setae), filled with an urticating toxin that could lead to serious dermatitis, conjunctivitis and pulmonary problems (summarized as lepidopterism) on contact.

OBJECTIVES

To determine the incidence of caterpillar dermatitis in a kindergarten population with three infested oak trees located in its enclosure.

METHODS

We made a survey by the use of a questionnaire that was handed out to all parents with children regularly visiting that kindergarten.

RESULTS

Twenty-four out of 47 (51%) questionnaires were returned and 10/24 (42%) children showing symptoms of lepidopterism were reported: 8/10 (80%) dermatitis, 5/10 (50%) pruritus, 5/10 (50%) respiratory distress, 4/10 (40%) malaise and/or fever and 1/10 (10%) conjunctivitis. Seven out of 10 visited a physician but the correct diagnosis was not posed in any case. Four out of 7 received medication (topical and/or systemic antihistaminics and/or steroids).

CONCLUSIONS

Lepidopterism, an airborne disease caused by the setae of the processionary caterpillar, is a growing public health problem because of the increasing numbers of outbreaks, and it is still underestimated. Children seem to suffer more often from general symptoms and airway affection than adults.

An epidemic airborne disease caused by the oak processionary caterpillar

The oak processionary caterpillar (Thaumetopoea processionea Lepidoptera) is found in several European countries. It usually lives in oak forests or on single-standing oak trees. The larva of from the 3rd to 6th developmental stage (instar) develops poisonous hair (setae), filled with an urticating toxin that may lead to serious dermatitis, conjunctivitis, and pulmonary affection (summarized as lepidopterism) on contact with the setae. In June 2004 more than 40 people including young children developed symptoms of lepidopterism after resting within 20 m of an infested oak tree. Only a few people had touched the caterpillars. All those with clinical symptoms of lepidopterism could be treated as outpatients, but several needed systemic steroids because of the severity of their complaints. Lepidopterism, an airborne disease caused by the setae of the processionary caterpillar, is a growing public health problem because of the increasing numbers of outbreaks.

Occupational allergy in laboratory workers caused by the African migratory grasshopper Locusta migratoria

BACKGROUND

Recent reports of fatal asthma cases associated with swarms of locusts affecting African countries have highlighted the importance of this insect in causing asthma morbidity and mortality. However, only limited information is available about the allergic health outcomes such as asthma and its determinants in exposed individuals. In this study, workers exposed to the African migratory locust Locusta migratoria were evaluated for allergic health outcomes as well as the nature of the offending allergens.

METHODS

Ten scientists and technicians exposed to locusts in a laboratory were investigated for locust-related allergy using questionnaires and immunological tests. The presence of allergy was determined by quantification of specific IgE and IgG to L. migratoria using the UniCAP system and via skin-prick testing (SPT). The allergens were characterized by Western blot and ImmunoCAP inhibition assays.

RESULTS

Six of the 10 workers experienced symptoms ranging from urticaria and rhinoconjuctivitis to asthma. Seven individuals demonstrated sensitivity on SPT and five had specific IgE antibodies to L. migratoria. Significant cross-reactivity was demonstrated for allergens in the locust faeces, body and wings but not to cockroach allergens. Novel allergens with molecular weights of approximately 70 kDa were identified in locust wings, which are distinctly different from other known allergen sources from locusts.

CONCLUSION

Exposure to L. migratoria allergens is a potential sensitizer in exposed individuals. Raised levels of locust-specific IgE can be readily quantified. The wings of this insect species have been identified as a novel allergen source.

Clinical effects of exposure to the White-stemmed gum moth (Chelepteryx collesi)

BACKGROUND

The White-stemmed gum moth (Chelepteryx collesi) can be found in eastern Australia. The clinical effects of injuries caused by its many spine-like hairs are poorly defined and concern about the numerous hairs that remain embedded following contact with the cocoon have led to heroic means of removal.

OBJECTIVE

To examine the clinical effects of injuries by the caterpillar or cocoon of the White-stemmed gum moth.

METHODS

Prospective observational study of caterpillar injuries from calls to the New South Wales Poisons Information Centre. Cases resulting from C. collesi exposure were included for analysis. Caterpillars and cocoons were expertly identified where available and a follow-up consultation of all patients was conducted. Information was collected on the circumstances of exposure, local and systemic effects and treatment.

RESULTS

From the 26 included cases, seven had confirmed caterpillar contact (all children aged 1-11), six had confirmed cocoon contact and 13 had exposures consistent with C. collesi, but no caterpillar was caught. All cases occurred in summer. Of 13 confirmed exposures there was no difference between caterpillars and cocoons, and these were considered together. Affected areas were hands, feet, or both, following C. collesi being handled or trodden on. Pain was reported in all 13 cases, one with severe pain. In 10 cases pain duration was < 60 min. Six subjects had more than 100 hairs embedded (small black dots). In three cases, the hairs were surrounded by swelling and yellow discolouration. Despite the attempted removal of multiple hairs, they remained embedded for prolonged periods but caused no sequelae.

CONCLUSION

The clinical effects of the White-stemmed gum moth were minor with local pain. Although hairs remained in all cases, they caused no problems. Complete removal of hairs is neither possible nor necessary, and painful and invasive methods should be avoided.

Prospective study of definite caterpillar exposures

Exposure to caterpillars results in a variety of clinical effects depending on the species involved. The aim of this study was to describe the clinical effects from caterpillar exposures within Australia. Cases were recruited prospectively from calls to a poison information centre. Subjects were included if they had a definite exposure and they had collected the caterpillar or cocoon. The caterpillars were identified to genus and species level where possible. There were 36 included cases: two were contact exposures to caterpillar contents, one was an ingestion of a caterpillar and the remaining 33 patients had definite reactions from caterpillar or cocoon exposure. There were five families of caterpillars identified in the study: Arctiidae, Limacodidae, Anthelidae, Lymantriidae and Sphingidae, many of which occur worldwide. Clinical effects ranged from severe pain to an urticarial response depending on the species involved. There were no adverse effects following ingestion in this study. Treatment consisted primarily of removal of the caterpillar or cocoon. Other treatment measures consisted of symptomatic treatment such as ice packs and antihistamines. This is the first prospective study of caterpillar exposures within Australia and demonstrates that exposures can result in a variety of reactions depending on the family and species involved.

Isolation and characterization of Tha p 1, a major allergen from the pine processionary caterpillar Thaumetopoea pityocampa

BACKGROUND

Pine processionary caterpillars induce dermatitis by a toxic-irritative mechanism. The existence of true allergic reactions to allergens from these caterpillars has been recently demonstrated by positive immediate skin prick tests and specific IgE determination by immunoblotting using crude larval extracts. The aim of this work was to purify allergens from the crude larval extract in order to characterize IgE-binding proteins from these caterpillars.

METHODS

Allergens were separated by ethanol gradient fractionation and reversed phase HPLC. The N-terminal amino acid sequence of a selected allergen was obtained after SDS-PAGE and transfer. The clinical relevance of this allergen was measured using sera from patients allergic to caterpillar.

RESULTS

An allergen with a molecular weight close to 15 kDa was purified. It was recognized by 9 out of 11 allergic patients (82%). Its N-terminal amino acid sequence had no homologies to any other protein already described in data bases. For this reason, no information about its biological function could be obtained.

CONCLUSIONS

This 15-kDa IgE-binding protein is a major caterpillar allergen and shows no homologies to other insect allergens already described.

Arthropod allergens and human health

Many species of arthropods are the sources of potent allergens that sensitize and induce IgE-mediated allergic reactions in humans. Most of these arthropod allergens are proteins, and the allergic response mechanism to these allergens is the same as it is for allergens from other sources such as plant pollens, molds, and foods. Aside from ingestion of crustaceans (shrimp, lobster), among arthropods, humans have the greatest contact with insects and mites, and as a result allergies to these two groups of arthropods have been the most frequently reported. Because of the large number of people affected by allergic reactions to stinging insects, cockroaches, and dust mites, many allergens of these organisms have been extensively studied, purified, and immunobiochemically characterized and for some recombinant allergens, produced. Cocktails of these recombinant allergens have the potential for use in diagnosis and immunotherapy. In this chapter, we review the insects and mites that induce allergic reactions. Where the information exists, the immunobiochemical characterization of the allergens and the frequency of sensitivity or clinical reactivity in the human population are also reviewed. As background, the beginning of this review includes sections that define allergens, explain the allergic reaction mechanism, and describe the methods for naming allergens.

Outbreak of caterpillar dermatitis caused by airborne hairs of the mistletoe browntail moth (Euproctis edwardsi)

Caterpillars may be an under-recognised cause of skin and eye reactions. We report a four-month outbreak of recurrent papulourticarial rash among staff and visitors at a community centre. Caterpillar of the mistletoe browntail moth The cause was eventually diagnosed as airborne hairs from (Euproctis edwardsi). caterpillars of the mistletoe browntail moth (Euproctis edwardsi), which infested a eucalypt tree growing in front of the centre. To our knowledge, this is the first clear case of airborne caterpillar hairs causing dermatitis in an indoor environment.

Envenomation by the billygoat plum stinging caterpillar (Thosea penthima)

We report the first case of envenomation by the billygoat plum stinging caterpillar, Thosea penthima Turner (Limacodidae). The sting, on the forearm, caused immediate burning pain and local wheal formation. Pain radiated up the arm and there was severe "crushing" chest pain lasting four hours. The local pain persisted for 10 hours and required opiate analgesia.

Hypertension and abdominal pain: uncommon presentation after exposure to a pine caterpillar

The pine caterpillar Thaumatopoea wilkinsoni is found in pine woods all over Israel. Contact with its hair usually results in local reactions. Systemic reactions after contact with caterpillar hairs are known in other caterpillar species, but have been described only once after contact with T. wilkinsoni. We describe a group of adolescents who were exposed to T. wilkinsoni while camping in a pine wood. Three of them were referred to an emergency department. They had severe pruritus, pain and edema at the contact sites, with papular and urticarial rashes. Two of the patients had abdominal pain and one patient had hypertension for several hours. The hypertension resolved spontaneously.

CONCLUSION

Skin eruptions are the most common manifestations of T. wilkinsoni contact, however, although systemic manifestations are rare, abdominal pain and hypertension may occur.