What is vitiligo?
Vitiligo is a relatively common acquired pigmented skin disease that manifests as a complete loss of pigmentation of the skin mucosa in a limited or generalized fashion.
It is caused by loss of melanocyte function in the skin, but the mechanism is not clear.
It can occur on all parts of the body, commonly on the back of the fingers, wrists, forearms, face, neck and around the genitals.
It can also occur on the vulva in women, mostly in young women.
There is no significant difference between the sexes, and the disease can develop in all age groups, but is more prevalent in adolescents.
The lesions are depigmented patches, often milky white or light pink, with a smooth surface and no rash.
The white patches are well-defined, with increased pigmentation at the edges compared to normal skin, and normal or whitened hair within the patches.
The lesions tend to occur on sun-exposed and abrasion-damaged areas, and are mostly symmetrically distributed.
The lesions are often symmetrically distributed and often arranged in bands according to the distribution of nerve segments.
In addition to skin damage, the lips, labia, glans and inner mucosa of the foreskin are often involved.
The disease has no conscious symptoms, but a few patients have local itching before or at the same time.
Vitiligo is often accompanied by other autoimmune diseases, such as diabetes, thyroid disease, adrenal insufficiency, scleroderma, atopic dermatitis, baldness, etc.
The specific subtypes
1. Limited type
(1) Focal type One or more white spots confined to one area, but not in segmental distribution.
(2) Unilateral type (segmental type) One or more white spots in a segmental distribution, which suddenly disappears at the midline.
(3) Mucous membrane type Only the mucous membrane is involved.
2. Dispersed type
(1) Common type Extensive and scattered white spots.
(2) Facial extremity type: distributed on the face and extremities.
(3) Mixed type with mixed distribution of segmental, facial extremity and/or common type.
3. Pancytopenia
(1) Pancytopenia: total or almost total loss of pigmentation.
More than 90% of vitiligo is disseminated, and the remaining vitiligo is more limited than generalized.
The disease can be divided into complete and incomplete according to the pigment loss at the lesion. The former reacts negatively to DOPA, melanocytes are lost, and treatment response is poor. The latter is positive for DOPA and the melanocytes are not lost but only reduced in number, with a high chance of cure.
