A 67-year-old man presented with a 6-month history of a psoriasiform rash that began on his toes and progressed over days and then weeks to involve the nasal tip and periungual areas of his fingers. There was a scaly, erythematous to violaceous, periungual eruption on all involved digits. The eruption also involved the proximal aspect of the nail fold, causing marked dystrophy and thickening of the nail plate (Figure 1). The nasal tip and aural helices were similarly involved with a violaceous hue and a significant degree of follicular-based scale (Figure 2). A potassium hydroxide preparation was negative. Importantly, the patient stated that he had been diagnosed as having an invasive poorly differentiated squamous cell carcinoma of the left tonsil (4 × 3 × 2 cm), with cervical lymphadenopathy (T2 N1 M0), several weeks after the eruption began. A skin biopsy specimen was obtained from the toe (Figure 3).
Webb KG, Malone JC, Callen JP. Acral Psoriasiform Eruption in a Man With Squamous Cell Carcinoma of the Tonsillar Pillar—Quiz Case. Arch Dermatol. 2005;141(3):389-394. doi:10.1001/archderm.141.3.389-b