Confetti-like Sparing: A Diagnostic Clinical Feature of Melasma

Melasma is a common pigmentary disorder often seen in patients with skin phototypes III to IV.1 Worldwide prevalence is variable. In a study by Werlinger et al,2 the prevalence of melasma in post-menopausal Latino women Irving in Texas was reported at 8.8 percent. On the other hand, Southeast Asian populations have had a reported prevalence of melasma as high as 40 percent.1 The etiology and pathogenesis of melasma remains poorly understood, but is thought to be a combination of various factors, such as ultraviolet (UV) exposure, genetics, and hormonal influences. Clinically, it is typically described as a Symmetrie, well-demarcated, irregularly shaped, macular hyperpigmentation most often affecting the face with characteristic distribution in various well-recognized patterns (centrofacial, malar, mandibular, mixed). Histologically, the abnormal pigmentation may be found in the epidermis, the dermis, or both. Treatment options include topical bleaching regimens, chemical peels, and light and laser modalities.3 However, complete clearance of hyperpigmentation can sometimes be difficult to achieve, and recalcitrant cases of melasma are not uncommon, leading to significant patient distress and physician frustration.4 Compounding the difficulty in treating melasma is the diagnostic uncertainty that occasionally aecompanies the patient presentation. Currently, there are no universally aeeepted clinical or histopathological diagnostic criteria for melasma. Additionally, the pathogenesis is unknown and often the exaet same treatment can result in different outcomes for what is supposedly identical disease. A recent Cochrane review concluded that the largest published reports on melasma in fact had poorly defined patient selection criteria,5 indicating that even the leading experts were not in agreement as to which patients should be included in a “melasma” study. Taken together, these facts suggest that although diagnostic uncertainty in regards to melasma is rarely publicized, it nonetheless exists. A common mimicker of melasma is simple accumulated actinic dyschromia. This is the well-known phenomenon of irregular dyspigmentation of the skin that occurs as part of the chronic photoaging process.6,7 It typically responds extremely well to various types of laser treatments, whereas those same treatments may be problematic in melasma. Other entities could potentially add to the confusion, such as solar lentigines, poikiloderma of Civatte, postinflammatory hyperpigmentation, drug-induced hyperpigmentation, and less commonly cafe au lait macules, nevus of Ota, nevus of Ito, and actinic liehen planus. Because each of the above entities present different therapeutic challenges to the treating physician, with varying degrees of response rates and treatment modalities, it is crucial to arrive at an accurate clinical diagnosis of melasma. To that end, the authors test the diagnostic Utility of a highly unique feature of melasma—confetti-like areas of sparing within the hyperpigmented patches giving the impression of hypopigmented macules. The authors term these areas “Fitzpatrick macules” and analyze their Utility in helping to establish a diagnosis of melasma.