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Fig. 59.2 A, Severe solar elastosis. The pale, light blue-gray material in the superficial dermis has largely replaced the normal highly eosinophilic collagen bundles. Also note the loss of the normal rete pegs in the epidermis (hematoxylin and eosin [H&E]). B, Cutis rhomboidalis nuchae. Severe solar elastosis and wrinkling of the posterior neck secondary to sun exposure that clearly demarcates from more–normal-appearing skin that is less sun-damaged. |
Solar (actinic) elastosis refers to the changes due to abnormal elastotic fibers (Fig. 59-2A) produced by fibroblasts in the papillary and superficial reticular dermis in response to UV light exposure. These abnormal elastotic fibers stain with elastic tissue stains; electron microscopy demonstrates that these fibers are similar, but not identical, to normal elastic fibers. Recent research suggests that they are the result of UVA damage to fibroblasts that results in the over-production and accumulation of elafin, which binds to elastic fibers making them resistant to normal degradation by elastase. Large aggregates of these fibers impart a yellowish color and account for the yellow leathery appearance of sun-exposed skin in geriatric individuals. Solar elastosis is often most easily appreciated in the posterior neck, where it is termed
cutis rhomboidalis nuchae (Fig. 59-2B).
Muto J, Kurodo K, Wachi H, et al: Accumulation of elafin in actinic elastosis of sun-damaged skin: elafin binds to elastin and prevents elastolytic degradation,
J Invest Dermatol 127:1358–1366, 2007.