Anaplastic nevus: It is present at birth or develops shortly after birth, and the unilateral distribution of depigmented spots lasts for a lifetime, with the face and neck, trunk, and proximal extremities as the preferred sites.
Anemic nevus: It is a congenital limited vascular development defect. The blood vessels in the affected area have normal structure but defective function, and the anemic nevus lesions cannot cause congestion response after rubbing.
Marshall-White syndrome: The skin of the palms and dorsal feet shows ischemic white spots due to vasospasm. It is usually seen in neurotic middle-aged men. It is manifested as pale white patches on the back of the hands, palms and dorsum of the feet, with a diameter of 2-4 mm, and when the upper limbs droop for some time, the pale white patches on the back of the hands and forearms are more obvious.
Simple furfuraceous rash: it occurs in children, also seen in young adults, the skin is more common in darker people. Typical lesions are round or oval light red spots with blurred edges, 0.5 to 2.0 cm in diameter or larger. After a few weeks, the pale red spots gradually change to pale white spots covered with a little bran-like scales. The number of lesions is variable and mainly distributed on the face.
Tuberous sclerosis: It is caused by the abnormal development of organs in the ectoderm and involves the nervous system, skin and eyes. 85% of patients can see depigmented spots, which are lobular, oval or irregular-shaped white spots, and can appear on the trunk and upper and lower extremities, which are more obvious under ultraviolet light.
Koyanagi-Harada syndrome: an endogenous uveitis common in Chinese and Japanese, often associated with meningeal irritation, auditory dysfunction, vitiligo and hair whitening and alopecia.
Pemphigus: patches of pigment loss at birth, which can occur anywhere, but commonly on the front side of the body such as the central face, forehead and abdomen.
Idiopathic punctate leukoplakia: most of them are round or oval, with a diameter generally not exceeding the diameter of a soybean cross-section and a maximum diameter not exceeding 25px, with a color gradually changing from pale white to porcelain white. The age of onset is reported to be as small as 3 years old, but the onset is mostly over 50 years old.
Flare furuncle: is a superficial fungal disease caused by Malassezia infection epidermal keratin layer. The disease is chronic, with mild inflammation, and usually without conscious symptoms. The damage is characterized by scattered or fused hypopigmented or hyperpigmented patches with furfuraceous desquamation, preferably on the chest, back.
Non-pigmented pigmentary incontinence: also known as Ito hypopigmentation disease. The cause of this disease is unknown, more women than men, and more than 50% of cases develop at birth or during infancy. There are two clinical types: the cutaneous type and the neurocutaneous type. It occurs mostly on the trunk or extremities and is seen as linear or banded depigmented patches with clear boundaries.
Albinism is a genetic leukoplakia caused by a deficiency or impaired synthesis of melanin in the skin and appendages due to tyrosinase deficiency or hypofunction. The patient has no pigmentation in the retina, the iris and pupils appear pale pink, and is photophobic. The skin, eyebrows, hair and other body hair are white or yellowish white. Albinism runs in families.
Vitiligo is a common acquired disease of limited or generalized skin pigmentation loss. It is caused by loss of melanocyte function in the skin, but the mechanism is not clear. It can occur throughout the body, commonly on the back of the fingers, wrists, forearms, face, neck, and around the genitalia.