Angiokeratoma is a formation on the skin consisting of expanded subepidermal capillaries and accompanied by hyperkeratosis and other keratinization disorders. It represents neoplasms of various sizes (from 2 to 15 millimeters) of reddish, brown or almost black color. Diagnosis is carried out on the basis of examination of the patient’s skin, dermatoscopy, histological examination of formations, with some types of angioceratomic genetic studies. Treatment is reduced to the removal of neoplasms by various methods – by surgical excision, cryodestruction, laser cauterization.
ICD 10
D18.0 L57.0
General information
Angiokeratoma are a manifestation of a special dermatosis of various origins, in which benign hyperkeratotic vascular formations form on the surface of the skin. For the first time one of the forms of such a disease (Mibelli’s angiokeratoma) was described in 1889, the other types of pathology were studied by various scientists in the period from the end of the XIX to the beginning of the XX century. The cause of the appearance of angiokeratoma are genetic and metabolic factors, while some varieties of the disease are inherited by an X-linked mechanism. The occurrence, age and sex distribution are highly variable for different forms of pathology, the localization of neoplasms on the body, as well as their number, varies from single angiokeratoma to multiple lesions of the skin.
Causes of angiokeratoma
Currently, dermatologists distinguish several main types of angiokeratoma, which differ not only in clinical picture, but also in etiology. Experts see embryonic malformations as the direct cause of the development of most types of angiokeratoma (limited non-uniform angiokeratoma of the trunk, angiokeratoma of the scrotum and vulva, solitary papular angiokeratoma). Sometimes the trigger factor for the appearance of such formations on the skin can be trauma.
The hereditary nature of the disease was revealed for the first time for Mibelli’s angiokeratoma, currently it is assumed that it is inherited by an autosomal dominant mechanism with incomplete penetrance. Fabry’s disease, which belongs to the group of lysosomal accumulation diseases, also has a pronounced genetic character – the development of angiokeratoma is one of the key symptoms of this condition. This pathology is caused by a mutation of the GLA gene located on the X chromosome, it is responsible for the structure of the enzyme alpha-galactosidase A. Disorders in the structure of the enzyme lead to the accumulation of ceramide trihexoside in cells and numerous anomalies, one of which is the formation of angiokeratoma.
Pathogenesis
The development of such benign neoplasms on the skin is caused by vascular disorders, in which a focus consisting of pathologically expanded capillaries is formed in the subepidermal layer. This is confirmed by the clinical picture – in almost all types of the disease, angiokeratoma initially represent small formations on the skin of pink color and delicate consistency. In the future, vascular disorders are joined by abnormalities of keratinization of the epidermis in the form of hyperkeratosis and acanthosis, neoplasms begin to roughen and often change their color almost to black.
Despite the variety of causes that cause the formation of angiokeratoma and some differences in their appearance, the histological structure of such formations is generally similar. Lacunar dilated capillaries are detected in the thickness of the dermis, which can sometimes be accompanied by cavernous cavities lined with endothelium. They lift the epidermis, acanthosis of varying severity is often found in the latter, sometimes the epidermal layer may be thinned. In the case of solitary papular angiokeratoma, thrombotic masses are often deposited in the dilated capillaries, in many ways they cause a rather dark coloration of the formation.
Symptoms of angiokeratoma
Localization, size and number of angiokeratoma are directly dependent on the form of the disease. In some cases, this also affects the prognosis of pathology, so determining its type plays an important role in diagnosis. To date, there are five main forms of angiokeratoma in clinical dermatology.
Mibelli ‘s angiokeratoma
Presumably a genetic disease with an autosomal dominant type of inheritance, but with incomplete penetrance. Affects mainly women, the first manifestations of pathology occur at the age of 10-15 years, often accompanied by other vascular and vegetative disorders – acrocyanosis, palmar or foot hyperhidrosis.
Angiokeratoma appear on the skin of the palms and the back of the foot, at first they look like small reddish dots. Over time, these formations reach sizes of 3-5 millimeters, change their color to cherry or purple, begin to rise slightly above the surface of the skin, are covered with horny layers. It has been noted that local or general cooling accelerates the formation and development of Mibelli angiokeratoma. In case of injury or spontaneous neoplasms can ulcerate and bleed.
Limited nonviform angiokeratoma
This is one of the forms of the disease caused by embryonic malformations. Often signs of skin changes can be noticed already at the birth of a child, but in some cases neoplasms occur in childhood and even adulthood. Localization of angiokeratoma can be different – hips, trunk, forearms. Most often there is a single formation with a diameter of 2-5 millimeters without a tendency to further growth, its color varies from red to almost black. Angiokeratoma can be easily injured with the development of bleeding.
Fabry’s disease
Hereditary pathology belonging to the group of lysosomal accumulation diseases. Since its transmission is linked to the X chromosome, mainly men suffer, however, cases of the development of this pathology have been described in heterozygous women, albeit in a milder form. One of the first manifestations of Fabry’s disease is neuropathic pain, then sweating disorders (up to anhidrosis) and the formation of angiokeratoma are detected. Neoplasms on the skin occur in childhood or adolescence, they are multiple in nature and can affect the skin of the trunk, limbs and even the mucous membrane of the mouth. Usually angiokeratoma in Fabry’s disease are small, light pink, of a soft consistency, the phenomena of hyperkeratosis on them are poorly defined. Among other symptoms of this disease, cardiac disorders and kidney damage up to chronic renal failure are more often found.
Fordyce ‘s angiokeratoma
Most researchers of Fordyce angiokeratoma refers to embryonic malformations, although there are assumptions about the hereditary nature of the disease. In this form, neoplasms occur on the scrotum or penis, Fordyce’s disease is detected somewhat less often in women – in this case, angiokeratoma appear on the labia. The first manifestations of pathology can be detected at different ages – from 15 to 70 years, usually the formations on the skin are of a single nature. The dimensions of Fordyce’s angiokeratoma are 2-5 millimeters, the surface is often smooth, sometimes with hyperkeratic layers. The neoplasm can be the cause of itching, when combing it is easily damaged and bleeds.
Solitary papular angiokeratoma
It also refers to embryonic malformations. Vascular neoplasm on the skin is detected at the age of 10 to 40 years, the localization can be different – the skin of the hands, trunk, head. The size of an angiokeratoma can reach 10 mm, quite often hyperkeratosis and vascular disorders cause an almost black color of the neoplasm. This circumstance often leads to an erroneous diagnosis of skin melanoma, which is refuted by histological studies.
Diagnostics
Diagnosis of angiokeratoma is made on the basis of data from a dermatologist’s examination, dermatoscopy, biopsy, followed by histological examination of the structure of neoplasms. The clinical diagnosis of Fabry’s disease also includes genetic studies and the study of some biochemical parameters of the body.
Upon examination, one or more (depending on the type of angiokeratoma) formations on the skin are detected, several protruding above its surface, the color varies from pink to almost black. As a rule, neoplasms are painless, except in cases when their traumatization has occurred. With careful pressure on the angiokeratoma with glass, it turns pale. Hyperkeratosis and layering are often detected on the surface of the formation, but sometimes (for example, in Fabry’s disease) they may not be observed.
In Fabry’s disease, in addition to dermatological changes, symptoms of disorders of other organs are taken into account in the diagnosis: for example, neuropathic pain, signs of left ventricular hypertrophy according to ECG data, kidney disorders. Ophthalmological examination of the fundus reveals retinal vein dilation, microaneurysms, hyperemia of the optic nerve discs.
Genetic diagnostics can detect mutations of the GLA gene, it is the most accurate, albeit rather complex analysis. Biochemical techniques also play an important role in determining the causes of angiokeratoma in Fabry’s disease, such as determining the activity of alpha–galactosidase A in tissues and leukocytes, the concentration of sphingolipids in blood plasma. Differential diagnosis is performed with some forms of hemangioma, melanoma, certain hereditary diseases (for example, Randu-Osler disease).
Angiocerate treatment
Taking into account the fact that in the vast majority of cases the immediate causes of angiokeratoma are unknown, etiotropic treatment of these formations does not exist today. Only in relation to Fabry’s disease, enzyme replacement therapy is used to eliminate the deficiency of alpha-galactosidase A. However, these drugs can only slow down or prevent the formation of new angiokeratoma, whereas such therapy does not work on existing formations.
To eliminate angiokeratoma , many local procedures are used:
- surgical excision;
- diathermocoagulation;
- cryodestruction;
- laser moxibustion.
Before prescribing treatment, it is necessary to make a histological examination of the formation to confirm the diagnosis and exclude conditions such as hemangioma and melanoma. In the case of elimination of such forms of angiokeratoma as limited, solitary or Fordyce disease, relapses most often do not occur. But, if the cause of the neoplasm is Mibelli’s or Fabry’s disease, even after complete removal of the vascular anomaly, new ones may appear on the same or other areas of the skin.
Prognosis and prevention
In most cases, the prognosis for angiokeratoma is favorable, even if the removal of neoplasms is refused. In rare cases, frequent traumatization of vascular anomalies of the skin causes mild forms of anemia, cases of malignancy or other complications are not described. The exception is Fabry’s disease, in the absence of treatment for this accumulation disease, severe vascular, heart and kidney damage is possible, which can lead to death. Before the development of enzyme replacement therapy, most male patients died of myocardial infarction, stroke and chronic renal failure until the age of forty.
