acquired hyperpigmentation disorder that occurs on sun-exposed areas of the face.
likely occurs when ultraviolet radiation triggers melanocyte proliferation and pigment deposition.
It is more common in women of reproductive age, particularly during pregnancy because estrogen and progesterone also stimulate melanocyte proliferation.
Additional risk factors include darker skin tones, thyroid dysfunction, medications (eg, anti epileptics), and cosmetic use.
Patients typically develop irregularly shaped, hyperpigmented macules of varying color (eg, light to dark brown, ash/blue) that occur in a symmetric centrofacial, mandibular, or malar distribution.
<aside> 💡 Melasma is not associated with systemic symptoms
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this patient's fatigue and dizziness are most consistent with normal third-trimester physiology (ie, slow venous return due to the enlarging gravid uterus) because her symptoms resolve with snacking and hydration.
Melasma is diagnosed clinically and requires no further evaluation. Management during pregnancy includes minimizing progression of the hyperpigmentation with sun exposure avoidance and broad-spectrum sunscreen use. Melasma typically resolves postpartum; areas that do not resolve can be treated with skin-lightening agents or topical retinoids after delivery.
(Choice D) A serum cortisol level is used to evaluate for adrenal insufficiency, which can present with hyperpigmentation and fatigue; however, the hyperpigmentation is typically generalized rather than focal, and the associated fatigue is usually not improved with food and hydration.