It is a disease that causes depigmented (non-pigmented) areas with the loss of melanocytes that give color to the skin, and can sometimes be seen together with uveitis and other autoimmune events.
prevalence. 1-2% in whites, more in blacks.
Age. It often begins in childhood or young adulthood.
There is no gender discrimination.
Race. It is a more important problem in people with dark skin.
Job. Depigmentation induced by chemicals occurs in janitors by contact with paraphenolic acid components or with hydroquinones and can be confused with vitiligo. However, they are considered as different diseases.
Genetic. It is often familial, but the exact route of transmission is not clear. Over four genes are thought to be responsible. In a meta-analysis of 777 patients, a significantly greater association with HLA-A2 was found in vitiligo patients than in the control group.
Etiology and Pathogenesis:
The starting point that causes vitiligo is unknown. There are three major theories. Presumably, each mechanism also plays a role in selected patients. There is convincing scientific evidence for each hypothesis.
Autoimmunity Hypothesis.An autoimmune reaction prevents the continuation of the normal course of melanocytes in the basal layer.
Neural Hypothesis. Vitiligo lesions often have a definite arrangement. This indicates that neurochemical mediators are responsible for the destruction of melanocytes.
Self-Destruction Hypothesis.A toxic mediator of melanin synthesis breaks down melanocytes.
Initially, melanocytes produce less melanin. Presumably in this early phase, the deterioration is reversible. This is explained by the better response to treatment when the treatment of the lesions is performed on time (early). The melanocytes are then destroyed.
Sometimes deeper hair follicle melanocytes are also destroyed, but often they remain relatively unaffected and represent a potential source for a new population of pigment-producing cells in the skin.
A fairly large group of diseases is associated with vitiligo. Some of these give a clue to the etiology of the disease. Thyroid disorders are a very common associated factor, present in approximately 30% of patients. Both hyperthyroidism (including Graves’ disease) and hypothyroidism (including Hashimoto’s disease) can occur. Other possible endocrinological diseases are Addison’s disease, insulin-dependent and adult-onset Diabetes mellitus. A wide range of other autoimmune diseases are also associated with vitiligo. These include Pernicious anemia, lupus erythematosus, systemic sclerosis, myasthenia graves, Crohn’s disease, primary biliary cirrhosis, Sjögren’s syndrome, and alopecia areata.
Although there are many triggering factors for vitiligo, they are often not clinically applicable. Vitiligo Köbner phenomenon can be quite dramatic. While patients are in the active phase, minor skin traumas during the development of new lesions can lead to vitiligo. Pronounced sunburn is also an interesting trigger. The speculation mentioned here is; Damage to melanocytes, perhaps even pushing itself to produce more pigment, triggers an autoimmune response after releasing its products.
Vitiligo can occur at any age, but it is often seen between the ages of 10-30. It has been reported that more than 50% of patients develop vitiligo in their 20s. Initially, small pallors or patches of white appear, which are easy to see on the skin or dark skin. Wood light is very helpful especially for pale people. First, a small number of patches with diameters ranging from one to several cm are observed. The patches increase in number and coalesce, forming interesting intersecting lesions. Patients often complain of itching, but the inflammation is never clinically visible. Sometimes, if it is due to sunburn, the lesions are red and painful.
The areas it tends to bite are the more pigmented skin areas, such as the palms of the hands, the genitals, the head, neck, armpits, and nipples. Hair may be unpigmented (acquired poliosis) or may remain in their natural color even if the scalp is involved.
Vitiligo is classified according to its clinical features.
focal:one or more patches, not segmental
Segmental:there is a pattern with one or more patches, dermatomes
Acrofacial:multiple lesion involving face and hands
General:irregular but widely distributed patches
Almost the entire body is depigmented. Normal skin is observed in patches, often
Combination of two or more patterns
If clinical findings support an associated disease, appropriate testing should be performed. New research focuses on its association with HLA-A2. Thyroid function tests should be checked.
Course and Prognosis:
Vitiligo is a very difficult disease. In a study, the rate of depression was found to be significantly higher and the quality of life was significantly lower in vitiligo patients compared to the control group. Usually, emotional problems are relatively infrequent, as patients know how to live with it. In some societies, vitiligo is confused with leprosy and patients are clearly excluded. There is a risk of severe actinic damage in unprotected areas in diffuse vitiligo. Low quality of life may be observed in patients with ocular problems.
If the disease has been present for years or predominates in the limbs, spontaneous resolution or response to treatment is unlikely. Vitiligo is more serious and more persistent in patients with atopic dermatitis. Re-pigmentation with many different arrangements is often from hair follicles.
A long list of recommended treatments for vitiligo supports the lack of a good approach. The cornerstone of treatment is to have a long conversation with the patient, the advantages and disadvantages of all treatments being used should be explained.
PUVA (Ultraviolet A light with Psoralen) . The main agent of systemic therapy is psorale and is combined with a natural light or UVA source.
Oral PUVA therapy
8-methoxypsoralen at a dose of 0.3 mg/kg 90 minutes before light exposure (if not tolerated, 0.6 mg/kg trimethylpsoralen 2 hours before exposure) is used.
PUVA-Sol therapy (Psoralen- sun therapy)
Trimethylpsoralen is used at a dose of 0.6 mg/kg (sometimes in lower doses) 2 hours before light exposure.
Patients start treatment for 5 minutes (between 10:00 and 15:00). The duration is increased to be applied in 5-minute increments up to 30 minutes. No additional treatment is given to the patient who applies this treatment three times a week.
PUVA bath treatment
8-methoxypsoralen is added to water at a concentration of 0.5 mg/liter. The patient is kept inside for 20 minutes. Initial dose 0.1-0.2 J/square centimeter
Regardless of the PUVA treatment option, the response of facial and neck lesions to treatment is over 60%. This rate is lower in lesions on the hands and feet. Patients should be careful about the use of antiscreen. PUVA therapy is not often used in children.
Beta- Carotene. It causes a yellow-orange skin color with the accumulation of the vitamin in the stratum corneum. It is given at a dose of 25-30 mg 3-6 times a day. The patient can adjust the dosage according to the discoloration of the skin. Carotenes are often harmless, but liver function should be checked before and several months after treatment. Many vitiligo patients are not satisfied with the replacement of white areas by yellow color. This treatment has no place in dark-skinned people.
Corticosteroids. The rate of repigmentation in a limited number of early lesions has been reported as 10-80%. Low or medium potency corticosteroids can be administered to patients once or twice a day. This treatment is most appropriate, especially in children. If steroid-induced acne develops, treatment should be discontinued for more persistent side effects.
Psoralens. Titration in UVA or sun exposure is very difficult with the use of topical psoralen. Many toxic reactions have been reported with 1% Oxsorelen lotion in the USA. In other words, if topical treatment is considered in a patient, the maximum concentration to be used in the PUVA unit is 0.1%, while it is 0.001% at home.
UV Radiation. Narrowband UVB (311nm)may be used in some patients.
Sunscreen agents. There are unclear situations regarding the use of these agents in treatment, and there are two underlying reasons. First, the skin with vitiligo does not have as great a risk of skin cancer as in albinos, and this is still valid. Secondly, with the use of sunscreen, the normal skin will not tan much and the contrast with the lesioned skin will be prevented.
Camouflage. Many concealer agents are available in many countries. In addition, various natural dyes and dihydroxyacetone are used.
Total Depigmentation . In cases where resistant and unsatisfactory results are encountered, normal skin color can be lightened and the whole body can be whitened and harmonized with the vitiligo area in patients with widespread vitiligo.
Surgical. Surgical intervention in vitiligo is the newest and most creative approach. Pigmented skin is grafted to the vitiligo patch, and often the transferred melanocytes repigment this area. The most suitable patients for surgical repigmentation are those with stable vitiligo. There are many techniques such as mini-punch graft, transfer of pure melanocyte cultures, mixed epidermal culture transfer.
exp. Dr. Nezih KARACA