This title designates a superficial fungal infection (tinea) that changes color (versicolor). The causative organism was originally called Malassezia furfur and is now called Pityrosporum orbiculare. Tinea versicolor typically causes numerous patchy scaling macules on the upper chest and back, proximal arms, and neck. Facial involvement may occur as shown. The lesions may be hypopigmented, as illustrated here, or brown-orange, depending on the skin color of the patient and the degree of recent sun exposure. The organism is believed to prevent either the formation of melanin or the transfer of melanosomes into keratinocytes. The formation of azelaic acid is another suggested mechanism for the resultant hypopigmentation. Although tinea versicolor usually makes its appearance after puberty, it can develop in childhood and is occasionally seen in breast-fed infants. Tinea versicolor is usually asymptomatic but may itch slightly. The organism cannot be cultured, but diagnosis is aided by the orange or brown glow of lesional skin under a Wood's light and by the “spaghetti and meatballs” appearance of clustered hyphae and spores on potassium hydroxide preparation.