Asymptomatic erythematous depression on the thumb

Sofia Antunes-Duarte ¹, Rita Pimenta ², Luís Soares-de-Almeida ³, Paulo L. Filipe ⁴

¹ Dermatology and Venereology Department, Hospital de Santa Maria, Unidade Local de Saúde Santa Maria, Lisbon, Portugal; Dermatology and Venereology University Clinic, Faculty of Medicine, University of Lisbon, Lisbon, Portugal; ² Department of Dermatology, Hospital Garcia de Orta E.P.E., Almada, Portugal; ³ Dermatology and Venereology Department, Hospital de Santa Maria, Unidade Local de Saúde Santa Maria; Dermatology and Venereology University Clinic, Faculty of Medicine, University of Lisbon; Dermatology Research Unit, iMM João Lobo Antunes, University of Lisbon. Lisbon, Portugal; ⁴ Department of Dermatology and Venereology, Unidade Local de Saúde Santa Maria; Faculdade de Medicina da Universidade de Lisboa, Dermatology Clinic. Lisbon, Portugal