The term lentigo encompasses an array of related hyperpigmented lesions, which include lentigo simplex, nevus spilus, agminated lentigines, solar lentigo, and lentigo maligna (see Table 2 ). In general, lentigo refers to a circumscribed brown spot resulting from an increased number of melanocytes in the epidermis (Ortonne et al., 2003). Although all forms of lentigines have some degree of increased melanocyte counts, this is characteristically seen in simple lentigines. On the other hand, solar lentigines are typified by increased melanin production. Solar lentigines are circumscribed, pigmented macules which are usually light brown, but vary in degree of color to jet black. They can range anywhere in size from less than 1 mm up to a few centimeters in diameter and, in areas of severely sun-damaged skin, may coalesce into even larger lesions (Ortonne et al., 2003). Histopathologically, a linear increase in melanocytes at the dermoepidermal junction is apparent, but pigment incontinence and cellular abnormalities are not noted (Bose & Ortonne, 1994). Solar lentigines are characteristically found on UVR exposed areas of the body, evolving after acute and, in particular, chronic exposure.
Photochemotherapy (PUVA) can induce lentigines in 40% to 50% of patients an average of 5.7 years after starting therapy (Ortonne et al., 2003). The appearance of these macules is directly related to the duration and intensity of the solar exposure (Hexsel, Mazzuco, Bohn, Borges, & Gobbato, 2000).
Involved sites of solar lentigines frequently include the backs of the hands, face, forearms, back, neck, and chest. Although the lesions are also referred to as senile lentigines because they typically occur after the 4th decade of life, studies show these lesions may occur in young, otherwise healthy adults seen in the first several decades of life. However, the prevalence directly correlates with increasing age as 90% of white adults age greater than 60 possess these "age" spots (Ortonne et al., 2003). The incidence is probably the same for both sexes, but is witnessed more often in Fitzpatrick phototypes I-III (Hexsel et al., 2000). Characteristics of lentigines are summarized in Table 3 .
Dermatology Nursing. 2004;16(5) © 2004 Jannetti Publications, Inc.
Cite this: Hyperpigmentation: An Overview of the Common Afflictions - Medscape - Oct 01, 2004.