Pathogenic to human skin caterpillars belong to the Thaumetopoeidae family and can cause skin reactions. The pine processionary caterpillar is the larval form of the Thaumetopoea pityocampa moth and is found in southern and central Europe. Small setae develop, shed, and can be airborne at the last larval stages of the caterpillar’s growth. If the setae come into contact with the skin, they can cause various reactions, particularly contact urticaria and papular rashes. Sensitization to the pine processionary caterpillar is common in people exposed to direct and prolonged contact with plantations infested by the pest. Processionary dermatitis most commonly occurs in occupational settings. Woodcutters, gardeners, chainsaw operators, stockbreeders, resin collectors, entomologists, lumberjacks, and other forestry personnel are particularly affected. The skin areas usually involved are the face, neck, forearms, interdigital spaces, and the dorsum of the hands. In addition to the skin, Thaumetopoea pityocampa can affect the eyes and rarely the respiratory tract. Despite the significant damage to humans and nature, this infestation is an underestimated problem.