Abstract Panitumumab is a monoclonal antibody against the epidermal growth factor receptor used in metastatic colorectal cancer; in addition to tumor cells, it acts on epidermal keratinocytes and on the outer root sheath and presents skin toxicity in up to 90% of cases. A scanning electron microscope was used to examine the eyelashes and hairs of a 65-year-old patient with eyelash trichomegaly, curly hair, and paronychia undergoing treatment with panitumumab. Grooving in the hair shafts were identified, which were more evident in the eyelashes. Similar to oral epidermal growth factor inhibitors (erlotinib and gefitinib), panitumumab can cause acquired pili canaliculi.

Abstract Cutaneous collagenous vasculopathy is a rare acquired idiopathic microangiopathy characterized by progressive development of diffuse asymptomatic telangiectasias and histologically by accumulation of collagen type IV around the affected vessels. It is diagnosed by its clinical history, confirmed by light microscopy with collagen-specific immunostaining. We report a case of a patient with extensive acquired telangiectasias on the left arm, clinically resembling unilateral nevoid telangiectasia. Dilated blood vessels with thickened walls were observed in the dermis. Immunohistochemistry with collagen IV antibodies revealed marked collagen deposition around the vessels, confirming the diagnosis. Transmission electron microscopy observed duplicate and triplicate vascular basal membrane associated with deposition of amorphous material around the membranes.

O Hidroa Vaciniforme é uma fotodermatose muito rara vista geralmente na infância. Uma paciente de 18 anos foi examinada, a qual apresenta lesões vesiculosas e necróticas varioliformes nas áreas fotoexpostas, que evoluem para cicatrizes atróficas, piorando no verão. A microscopia óptica mostrou necrose epidérmica com infiltrado linfocítico. Houve pouca melhora com uso de filtros solares.

Hydroa Vaciniforme is a very rare photodermatosis that is mainly seen in childhood. An 18 year old female student reported that since the age of 5 she has been suffering necrotic lesions and vesicles lesions in exposed areas, leaving asymptomatic varioliform scars, which worsened in summer. Light microscopy showed epidermal necrosis with lymphocytic infiltration . Sunscreens were prescribed with light improvement.