Contents
Vitiligo is a defect in which the actual pigment disappears. We distinguish several of its varieties, which we group according to the source of the problem and the place of its occurrence.
Chemical albinism
Chemical vitiligo is discoloration resulting from contact (usually professional) with bleaching substances. This is due to industrial exposure to hydroquinone (an antioxidant in the leather and rubber industries which completely destroys melanocytes), tertiary parabutylphenols and amylphenols (disinfectants used in healthcare).
Initially, changes in the form of irregular spots are visible on the hands at the points of contact. Then, due to the absorption of bleaching substances, discoloration may occur in various distant parts of the body. Hepatosplenomegaly and inflammation of the thyroid gland have been observed after phenolic derivatives.
Prognosis: If a certain pool of undamaged melanocytes remain, they are a source of re-pigmentation.
Treatment: Chemical albinism is treated with PUVA in various variants.
Partial albinism
Partial albinism is a limited permanent lack of pigment, usually affecting the skin of the face, caused by an inherited lack of melanocytes. Partial albinism is caused by autosomal dominant inheritance, dependent on the mutation of the c-kit proto-oncogene on chromosome 4q12. This gene is responsible for the movement of melanocytes during embryogenesis. As a result of its damage, some parts of the body lack melanocytes. This type of vitiligo occurs less than once in 20 people.
Syn.: Piebaldismus, piebaldism, partial albinism, white birthmarks, white fringe syndrome.
Hist.: The electron microscope image is decisive. There are no melanocytes, melanosomes and melanin.
DR: Vitiligo, which often affects parts of the distal limbs and tends to spread the lesions.
Discoloration in partial vitiligo occurs from birth and is limited in nature. In typical cases, discoloration is most pronounced in the midline of the body. They occupy the scalp (tufts of white hair known as limited graying), the center of the face, the breastbone, the upper abdomen, and the elbows and knees. Completely white areas have “islands” of pigmented skin. They are surrounded by a darker outline. The remaining regions of the skin are normal in color.
Prognosis: Discoloration shows stability.
Treatment: Melanocyte transplantation seems to be a justified treatment for partial vitiligo, as the effects are permanent. The conservative method consists in cosmetic masking of changes.
Partial hair albinism
Partial hair albinism is the white tuft of hair above the forehead, sometimes in the occipital area, which is associated with a local lack of melanin, often medially in the frontal area.
syn.: Piebaldism, partial albinism.
Epid.: Frontal, occipital area.
Wedge.: Irregular, sharply defined area of light, colorless hair.
Hist.: Hair with normal histopathological structure, without dye.
DR: Waardenburg syndrome, poliosis.
Treatment: No specific treatment.
Lit.: [1] Hazan C.: Piebaldism. Dermatol Online J 2005, 30; 11-8.
Syphilitic albinism
Vitiligo syphilis (Fig. B-4) is a symptom of period II recurrent syphilis, it occurs almost exclusively in women on the side surfaces of the neck, nape and trunk. The changes usually appear 6 months after the infection. They have the character of small discolored spots a few millimeters in diameter, of a similar size and shape, and a mesh-like arrangement.
syn.: Leukoderma syphiliticum.
DR: Pityriasis versicolor, vitiligo.
Nail vitiligo
Vitiligo of the nails, leukonychia, these are porcelain-white spots moving distally as the nail grows. Nail vitiligo is thought to be the result of a disorder of keratinization in the nail plates, similar to parakeratrosis in the skin. Minor injuries, especially during eponychium excision, play a certain role in the formation of leukonychia. Vitiligo of the proximal parts of the nails combined with onycholysis of their distal parts may occur in Raynaud’s syndrome, which may be related to the blood supply disorders encountered here in the area of the hands. Leukonychia totalis can also be inherited in an autosomal dominant manner, as is the case in Bart-Pumphrey syndrome (bulging metacarpophalangeal joints, sensory deafness and leukonychia) and in Bushkell-Gorlin syndrome (multiple sebaceous cysts, kidney stones and leukonychia).
Causes of nail vitiligo
Nail vitiligo is thought to be the result of a disorder of keratinization in the nail plates, similar to parakeratrosis in the skin. Minor injuries, especially during eponychium excision, play a certain role in the formation of leukonychia. Vitiligo of the proximal parts of the nails combined with onycholysis of their distal parts may occur in Raynaud’s syndrome, which may be related to the blood supply disorders encountered in the hands. Leukonychia totalis can also be inherited in an autosomal dominant manner, as is the case in Bart-Pumphrey syndrome (bulging metacarpophalangeal joints, sensory deafness and leukonychia) and in Bushkell-Gorlin syndrome (multiple sebaceous cysts, kidney stones and leukonychia).
Clinical forms of leukonychia:
Leukonychia punctata is the most common form of nail vitiligo. There are numerous small spots with a diameter of 1-2 mm in the nail plates. Leukonychia striata are elongated white streaks of varying width, running distally from the lunula (meniscus) and often tapering at the free edge of the plate. Leukonychia transversa corresponds to the Mees and Muehrcke bands. The Mees bands are snow-white, have blurred edges, and extend across the width of the plate, which is often hazy lunula. These changes can also be dotted and irregular in shape. They are a consequence of a sudden damage to the matrix after poisoning with arsenic, antimony or thallium, and also appear after severe infectious diseases with high fever. The Muehrcke bands are white stripes that also extend across the entire width of the plate. They are a non-specific symptom of systemic changes in the nail matrix that occurs in patients with hypoalbuminaemia or during cancer chemotherapy. Leukonychia totalis takes up entire nail plates, which are chalky white and brittle.
Hist.: Histopathological studies have shown that the refraction of reflected light is caused by fine granules in the cytoplasm of the nail cells.
DR: Nail vitiligo differs primarily from the white discoloration of the nail plates in dermatophyte onychomycosis (leukonychia mycotica). Viewing the nails under magnifying glass is helpful here. In the case of infection of the nail plate by dermatophytes, whitening is the result of the characteristic symptoms of the transverse or branch mesh, which are pathognomonic for this disease.
Treatment: Treatment of leukonychia is ineffective.
Prognosis: In some cases, the changes may resolve spontaneously with the growth of the nail plates.
Lit.: [1] Baran R., Perrin C.: Transverse leukonychia of toenails due to repeated microtrauma. Br J Dermatol 1995, 133; 267-69. [2] Grossman M., Scher R.K.: Leukonychia: review and classification. Int J Dermatol 1990, 29; 535-41.
Pseudo-albinism
Vitiligo is a reversible discoloration of the epidermis associated with the disappearance of skin lesions. The causes of pseudo-vitiligo are related to a variable deposition of pigment in diseased skin, usually due to the coverage of the lesions with light-reflecting scales or the peeling of the epidermis on previously tanned skin. Often present in psoriasis (especially after phototherapy) and atopic dermatitis, the so-called white dandruff. Another cause may be the appearance of a contrast between the discolored surroundings of the lesion during the treatment of psoriasis with cygnoline.
syn.: Pseudoleucoderma, pseudoleucoderma psoriaticum, white dandruff.
Treatment: The changes are self-limiting. You can either accelerate the disappearance of tan in areas around the lesions using exfoliating agents, or tan the lesions (after the previous disease has completely subsided), while intensely lubricating the skin.
DR: Pityriasis versicolor, syphilitic albinism.
Pseudo-angiospastic albinism
Pseudo-angiospastic albinism is often seen in girls as whitish areas on the distal parts of the limbs and / or buttocks. The cause is spasm of the superficial vessels of the skin. Symptoms worsen when you feel cold or emotional. This unit in English in German it is called Weissfleckung (white spot disease).
Generalized congenital albinism
Generalized congenital albinism, albinism, is a lack of melanin in the skin, hair and eyes resulting from inborn disorders of its production and transmission. The main two types of albinism are tyrosinase negative i tyrosinase-positive. The first is completely free of tyrosinase and is the most severe. The cause is defects on chromosome 11q14-21.
Patients with generalized vitiligo have completely white skin, white hair, and blue eyes. They never sunbathe. They are easily sunburned. They show a high risk of developing actinic keratosis, basal cell carcinomas and amelanotic malignant melanoma. Their melanocytic nevi are pale or red. The lack of melanin in the retina of the eye causes the appearance of red pupils. Tyrosinase-negative albinos suffer from severe visual acuity problems. Tyrosinase-positive albinism is conditioned by a 15q11 chromosome defect. This variety is the most common. It is about twice as common in the black race as compared to the white race. Individual varieties differ in the degree of melanin deficiency. In contrast, the mode of inheritance is autosomal recessive. Black tyrosinase-positive patients are completely white at birth. Then their skin turns pink or cream gradually. Their hair is usually yellow-brown, while the iris is blue or yellow-brown. If there are freckles or melanocytic moles – they are pigmented.
Congenital hair albinism – is a disease caused by a defect in melanin synthesis, which is the cause of the complete or partial lack of melanin, manifested by complete or partial discoloration of the hair.
Syn.: albinism.
Loc .: Any area of the body.
Clinical: Hair can be completely colorless, light yellow to light brown.
Hist .: Hair with normal histopathological structure, without dye.
DR: Poliosis, sivienie.
But: No specific treatment, photoprotection is indicated.
Year: Good.
Lit.: [1] Russell-Eggitt I.: Albinism. Ophthalmol Clin North Am 2001, 14; 533-46.
Source: A. Kaszuba, Z. Adamski: “Lexicon of dermatology”; XNUMXst edition, Czelej Publishing House