Table of Contents
Definition of Vitiligo
Vitiligo is a condition of the skin, mucous membranes, and sometimes the hair. It can be observed as a focal or disseminated depigmentation and hypopigmentation of the skin. For this reason, it is also known as leukoderma.Melanocytes are destroyed in a process of focal apoptosis. There is no resultant structural or functional loss of the affected areas of the body.
Vitiligo is not infectious and occurs before the age of 20 in over 50 % of all cases. The worldwide prevalence of this disease is 0.5 %, and in India, this rises in some regions to 10 – 20 %.
Forms can be differentiated by their clinical distribution and localization.
- Localization: There are usually focal areas of depigmentation.
- Vitiligo vulgaris is the most common form of vitiligo, affecting 78 % of patients. All of the integument, mucous membranes, hair, and the genital area are affected.
- Acrofacial Vitiligo occurs in the face, especially in the periocular and periorbital areas. The outer extremities, i.e. hand and feet, are also affected.
Etiology of Vitiligo
The etiology of vitiligo is unexplained to date. There appears to be a genetic predisposition, however, in most cases.
Basically, it can be assumed that this condition is an autoimmune reaction: Specific auto-antibodies or cytotoxic T-cells destroy melanocytes either temporarily or permanently .
A further possible cause is a metabolic genesis. Due to defective tetrahydrobiopterin and catalase activity, oxidative processes are disrupted and oxidative stress occurs.
Neurogenic processes also appear to play a role. In this case, stress-induced mediators could be responsible for the activation of the immune system.
The primary manifestation of the disease often occurs after strong UV exposure or mechanical skin damage.
Symptoms of VitiligoThe efflorescences are depigmented, sharp and irregularly circumscribed maculae. Poliosis (depigmentation or whitening of the hair) can occur. Follicular repigmentation takes place by spreading from the periphery.
Vitiligo is either chronic and progressive or manifest in periodic exacerbations. In rare cases, there can be a spontaneous remission.
Diagnosis of Vitiligo
- The clinical picture is decisive in the diagnosis of vitiligo.
- The histology is unremarkable, with the exception of the lack of melanocytes.
- Wood’s lamps (364nm) display a white fluorescence of the hypopigmented maculae.
- Other autoimmune diseases should be ruled out in the diagnosis.
Treatment of Vitiligo
Spontaneous remission is possible; however, it is quite rare. Typically, vitiligo is treated with phototherapy. This is then combined with other measures that can strengthen the melanogenic effect.
The first choice of treatment is phototherapy in short and regular sessions. UVB with a wavelength of 311 nm is utilized. The duration of treatment is normally around a year and leads to repigmentation in about 75 % of patients.
PUVA therapy is a combination of UV-A light and the naturally occurring chemical compound psoralen. Psoralen has a photosensitizing effect. Before the UV radiation, psoralen is either taken orally or applied topically. In a PUVA water bath, the patient lies in a bath tub filled with water containing psoralen. Radiation follows the immersion in the bath.
Topical glucocorticoids are used for local treatment. These dermocorticoids have an anti-inflammatory and immunosuppressive effect. Undesirable side effects include atrophy of the skin, telangiectasia, and intolerance reactions. For these reasons, topical glucocorticoids should not be applied extensively or for longer periods of time.
Tacrolimus and Pimecrolimus are topical calcineurin inhibitors. They are immune modulators as they inhibit the activation and proliferation of T-cells. It should be taken into account that in the United States, these calcineurin inhibitors are only indicated for the treatment of atopic dermatitis, and the US Food and Drug Administration issued a black box warning for Tacrolimus and Pimecrolimus in 2005/2006, warning about a possible risk of cancer. Many scientific studies however dispute this fact and show very promising treatmetn results.
Vitamin D analogs such as calcipotriol also have an anti-inflammatory effect. In addition to this, they promote the differentiation of normal skin. The prescribed dosages should not be exceeded as this could lead to the development of systemic side effects such as hypercalcemia.
Glucocorticoids have an immunosuppressive effect. Oral administration of glucocorticoids can be used as a short term therapy. Longer term treatments of this type are not recommended due to the side effects.
Areas affected by vitiligo should be rigorously protected from sunlight. The skin is very sensitive due to the lack of pigmentation. Vitamin D supplements should be taken as a deficiency can occur due to a lack of exposure to natural sunlight.
Camouflage is a cosmetic concealer for the affected areas. It mimics the color of healthy skin. Additionally, self tanning lotions might be employed for a better cosmetic result. In extremely advanced cases of generalized vitiligo, depigmentation using bleaching agents could be considered.
In autologous melanocyte transplantation, pigment cells are harvested from the patient. These melanocytes are cultivated in vitro for several weeks. The epidermis of the areas affected by vitiligo is removed using a laser. The colonies of cultured melanocytes are then applied on the skin.
Overview of Treatment Options
|Phototherapy||UV-B 311 nm, Excimer laser, PUVA, KUVA|
|Local Treatment||Glucocorticoids, calcineurin inhibitors, vitamin-D analogs|
|Systemic Treatment||Glucocorticoids can be utilized as a short-term treatment.|
|Supporting Measures||UV protection und cosmetic treatments such as Camouflage|
|Other Treatments||Melanocyte transplants (very costly), split-skin graft|
To this day, there is no cure for vitiligo. Treatment options can positively influence its development and possibly lead to repigmentation. In any case, sufficient protection from sunlight is necessary to prevent malignant skin diseases.
Popular Exam Questions on Vitiligo
Solutions can be found below the references.
1. At what age does vitiligo present itself in half of all cases?
- At adolescence.
- Between 1 and 6 years old.
- From the age of 50.
- From birth onwards.
- From the age of 60.
2. Which is the most common form of vitiligo?
- Localized vitiligo
- Acrofacial vitiligo
- Universal vitiligo
- Vitiligo vulgaris
- Segmental vitiligo
3. How can the hypopigmented maculae be visualized in diagnosis?
- UV B 311nm
- Wood’s lamp
- Contrast media