Pigmentary Disorders

A 6-month-old infant presents with generalized hypopigmentation of skin and hair, nystagmus, and photophobia. Genetic testing reveals a mutation in the *TYR* gene. This clinical presentation is most consistent with which type of albinism?

A 22-year-old male develops dark brown macules and patches on his back following a severe acne breakout. These lesions are flat and correspond to the areas where acne lesions were previously present. This condition is best described as:

A 35-year-old pregnant woman presents with symmetrical, brownish patches on her cheeks, forehead, and upper lip, which she noticed during her current pregnancy. She is diagnosed with melasma. Which of the following is considered the gold standard topical treatment for melasma, often referred to as Kligman's formula?

A 4-year-old child is brought to the clinic for evaluation of multiple light brown, flat macules on the trunk and extremities. On examination, six such macules, each greater than 0.5 cm in diameter, are noted. This finding, in conjunction with other potential signs, should prompt further investigation for which of the following conditions?

A 30-year-old female presents with progressively enlarging, well-demarcated, milky-white patches on her face, hands, and trunk. Wood's lamp examination accentuates the lesions. Which of the following is the most likely underlying pathological mechanism?