[Dermoscopic signs as predictors of non-response to imiquimod treatment in superficial basal cell carcinoma]. / Criterios dermatoscópicos como predictores de ausencia de respuesta a tratamiento con imiquimod en carcinomas basocelulares superficiales.

BACKGROUND: To describe the dermoscopic features in superficial basal cell carcinoma that are associated with a poor therapeutic response to imiquimod treatment. METHOD: Clinical and dermatoscopic photographs of 56 superficial basal cell carcinomas of different patients were compared retrospectively, assessed in our office for five years and treated with topic 5% imiquimod five days a week for six weeks. The different dermatoscopic signs of the lesions were identified and the association of each of them with the response to treatment was assessed. RESULTS: A total response to treatment was achieved by 69.5% of the lesions of patients treated with imiquimod. Dermatoscopy of responding lesions showed a higher frequency of lesions with in focus gray dots (43.6%) and multiple erosions of less than 2 mm (61.5%), without observing statistically significant differences. Within the group with poor response to treatment, a greater number of lesions were found with the presence of arborizing telangiectasias (58.8%), blue-gray ovoid nests (41.1%), ulceration (58.8%), shiny white-red structureless areas (82.2%) and chrysalis (41.2%). The areas in blue-white veil areas (23.5%) and rainbow pattern (23.5%) were only observed in non-responding lesions. Both groups were similar regarding age, sex, diameter of lesions and frequency of some dermatoscopic signs: fine short telangiectasias, gray blue globules, arc-leaf areas and cart-wheel structures. CONCLUSION: The study identified dermatoscopic criteria that are significantly associated with a worse response to treatment with imiquimod. In contrast, we found no dermatoscopic signs that correlate specifically to a complete response to treatment.

[Secondary effects of topical application of an essential oil. Allergic contact dermatitis due to tea tree oil]. / Efectos secundarios de la aplicación tópica de un aceite de esencial. Dermatitis alérgica de contacto a aceite de árbol de té.

BACKGROUND: Tea tree oil is an essential oil, whose use is increasing in our setting, due both to its supposed medicinal effects and to its aromatic properties. We describe our experience with allergic contact dermatitis following the application of this oil. MATERIAL AND METHODS: Five patients in the last 5 years (0.4% of all the patients studied in specialized consultation) reacted to a 5% concentration of tea tree oil in Vaseline. RESULTS: All the patients presented strong reactions, and in all cases these were considered relevant. Three of them also reacted to oxidized d-limonene, one of the components of tea tree oil, which is present in our standard series. CONCLUSIONS: Different cases have been described in the literature on allergic contact dermatitis due to tea tree oil, but until recently it was infrequent in our setting. With the increased popularity of alternative and natural therapies we have witnessed several cases of sensitization to this essential oil, which had been used to treat several supposedly "infectious" skin diseases, but which were very probably different forms of dermatitis.