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Abstract #21251 Published in IGR 10-2
Humans and pine caterpillar (Thaumetopoea pityocampa Schiff)
Bonamonte D; Profeta G; Foti C; Angelini GAnnali Italiani di Dermatologia Allergologica Clinica e Sperimentale 2007; 61: 91-98
The pine caterpillar, Thaumetopoea (T.) pityocampa Schiff, is a phyto- and xilophagus lepidopteran, responsible of the delay in the growth or the death of some types of pines, among which maritime pine present on the Mediterranean coasts, and cedars. Apart from the damage to nature, the pine caterpillar causes papulo-urticarious reactions, generally of the strophulus type, as a result of the urticant hairs present in the last three larval stages (L3, L4, L5), in humans and domestic animals (dogs, sheep). The urticant hairs, hollow on the inside, have no hole or pores and therefore must be broken in the skin to release their urticant substance. Although the dermatitis occurs among out-door professionals, it is primarily extraprofessional. Contamination generally occurs in pinewoods, rarely in cities, although infested pines may even found in cities. There are various means of contamination: direct contact with the nest or the processional caterpillar, and indirect contact with the hairs suspended in the air. This contact eruption can be observed in the late spring and particularly from April to June, among campers and picnic lovers. The pathology induced by T. pityocampa Schiff involves the skin, eyes and in rare cases the airways. The cutaneous eruption is favored by sweat, has its onset 1-12 hours after contact with the hairs, and presents subjectively with intense and continuous itching. The eruption consists of papulous, excoriated, and pinkish lesions on an oedematous base. Rarely, the lesions can be bullous. Each lesion evolves over 3 to 4 days and leaves an hyperchromic outcome that lasts about 2 weeks. Diagnosis is aided by the onset of the same eruption in other members of the patient's party, by the sites affected, and mainly by case history describing a recent stay or walk in or near pinewoods. The pathogenetic mechanism of the affection is mechanic (due to the penetration of the hairs inside the skin), and pharmacological (due to the release of the urticant histamine-liberating substance) in nature. The pharmacological mechanism may be direct in the action, and probably also IgE-mediated. Lesions to the eyes can be early or late. The former manifest with intense burning sensation, hyperemia, and edema of the conjunctiva and eyelids This is followed by photophobia, abundant secretion, and conjunctival nodules the size of peppercorns, as a reaction to the hairs (ophthalmitis nodosa). Late lesions are secondary to the penetration of the hairs inside the eye; the clinical pictures include chreratitis, iritis, uveitis, cataract, nodules of the iris, and finally glaucoma. Despite the considerable damages to humans and nature, the caterpillar pine infestation is a problem underestimated; the same medical literature contains rare reports, and often the knowledge of the problem is referred to the media. LA: Italian
Dr. D. Bonamonte, Clinica Dermatologica I, Policlinico, Piazza Giulio Cesare 11, 70124 Bari, Italy. D.bonamonte@dermatologia.uniba.it
Classification:
9.4.20 Other (Part of: 9 Clinical forms of glaucomas > 9.4 Glaucomas associated with other ocular and systemic disorders)
