Macrolunula: Case Reports of Patients with Trauma-associated Enlarged Lunula and a Concise Review of this Nail Finding.

The lunula refers to the visible portion of the distal nail matrix that extends beyond the proximal nail fold. Macrolunula, or enlarged lunula, is not only a physiologic variant but also has been associated with a variety of local and systemic disorders. Macrolunula has been described in congenital conditions including hereditary onycho-osteodysplasia, neoplasms such as superficial acral fibromyxoma, as well as iatrogenic causes as in the topical administration of hydrocortisone; it can also occur in systemic disorders including hyperthyroidism, ischemia, leprosy, and scleroderma. While macrolunula has been described in self-induced trauma secondary to habit-tic deformity, we observe in this case report that any mechanism of trauma to the nail unit may produce enlargement of the lunula.