Invisible palmar needles: thyroid disorder associated spiny keratoderma and the importance of proper light for visualization.

Spiny keratoderma is a rare skin condition that presents on the palmar and plantar surfaces of the hands and/or feet. This condition is difficult to appreciate under ambient lighting but can be both physically and emotionally distressing to patients. Furthermore, because of the association with various neoplasms and systemic diseases, timely diagnosis and appropriate follow-up is of importance. We evaluate a case of spiny keratoderma in a patient with recently diagnosed hypothyroidism and emphasize the importance of proper lighting during a dermatology-focused physical examination. The patient's palmar lesions were only appreciable under LED light and with physical examination. A biopsy of the lesions confirmed the diagnosis of spiny keratoderma.