Idiopathic guttate hypomelanosis is a dermatological disease of unclear etiology, manifested by a focal violation of pigmentation of the skin. It is considered one of the most common variants of hypomelanosis. Symptoms of this disease are light spots up to 10 millimeters in size, localized on the flexor surface of the knee and elbow joints, shoulders and chest. Diagnosis of teardrop-shaped hypomelanosis is carried out on the basis of dermatological examination data, analysis of the patient’s anamnesis, in controversial cases, a skin biopsy can be performed followed by histological examination of tissues. Etiotropic treatment of the disease has not been developed, patients are prescribed glucocorticosteroid drugs, retinoid-based drugs, protection from ultraviolet radiation is recommended.
Idiopathic guttate hypomelanosis is a focal violation of skin pigmentation of unclear (possibly polymorphic) genesis, presumably due to delayed recovery of melanin against the background of its accelerated destruction by ultraviolet and other factors. This condition is one of the most common variants of hypopigmentation of the skin, mainly affects women over the age of 30-40 years. For this reason, some dermatologists attribute idiopathic guttate hypomelanosis to one of the variants of photoaging of the skin – it has been noticed that exposure to ultraviolet light accelerates the development of this disease. The literature also describes family cases of pathology, which may indicate its genetic nature, but there is no reliable confirmation of this theory at the moment. According to modern ideas, idiopathic guttate hypomelanosis is a dermatological condition, in the development of which a number of different factors are involved – age-related changes, external influences (temperature changes, UFOs), genetic characteristics of the patient.
Melanocytes, skin cells that contain the brown pigment melanin, which performs a protective role (absorption of ultraviolet radiation), are responsible for the characteristic color of human skin. The saturation of the skin color depends on the number of melanocytes and melanin in them. When exposed to a number of factors of different nature, there may be a lack of this pigment – the cause is either accelerated destruction of melanin, or its insufficient formation. These processes underlie any type of hypopigmentation of the skin. It is assumed that in the case of idiopathic guttate hypomelanosis, there is a combination of two phenomena – intensive destruction and delayed formation of melanin. Statistics indicate that women with skin types 1, 2 and 3 are more susceptible to this pathology – that is, persons with initially low melanin levels and weak protection from ultraviolet radiation.
There is no reliable data on the etiology of teardrop-shaped hypomelanosis at the moment, it was found out that its development accelerates with prolonged exposure to the sun. Therefore, it is assumed that the role of the triggering factor can be played by ultraviolet radiation. The predominant development of teardrop-shaped hypomelanosis in older women allows it to be attributed to a type of photo-aging of the skin, but it remains unclear why it occurs in some individuals and does not manifest itself in others. In recent years, it has been determined that most patients have the same type of antigens of the main histocompatibility complex (HCGS) – HLA-DR8, which indicates the role of genetic and immunological factors in the development of pathology. An additional proof of this assumption is the discovery of familial forms of teardrop-shaped hypomelanosis, however, not all cases of the disease are explained by this.
The onset of teardrop-shaped hypomelanosis in most cases occurs at the age of 35-45 years, occasionally it can manifest earlier, especially with the abuse of sunbathing or visits to tanning salons. The primary localization of hypopigmentation in this condition is the skin of the flexor surface of the knee joints – it is there that light spots with a diameter of several millimeters of rounded shape appear. For a long time, this symptom of teardrop-shaped hypomelanosis remains the only one, most patients do not go to the doctor because of the weak severity of manifestations and imperceptible localization of lesions.
Over time, foci of hypopigmentation occur on the forearms, flexor surface of the elbow joints, shoulders. Then teardrop-shaped hypomelanosis spreads to the skin of the chest, where the size of the lesions can reach 1 centimeter. The areas of hypopigmentation have a rounded shape and clear boundaries, usually do not merge with each other – the clinical picture of the pathology is similar to the “drops” of disturbed pigmentation scattered throughout the body, which gave the name to the disease. Teardrop-shaped hypomelanosis rarely leads to damage to the skin on the face, limited to the lower and upper extremities, the chest area, occasionally spreading to the back and abdomen. There are no subjective symptoms (itching, burning, soreness) in this pathology.
Diagnosis and treatment
Determination of teardrop-shaped hypomelanosis in dermatology is carried out by examining the skin and questioning the patient, in controversial cases, skin scraping or biopsy is performed with subsequent microscopy of samples. When examining the skin, it is recommended to use a Wood lamp, since with its help it is possible to identify areas of hypopigmentation even on very light skin. Considering that most often teardrop-shaped hypomelanosis develops in people with 1-3 skin types, in some cases it is very difficult to detect foci of disturbed pigmentation on unburned areas without special equipment. No other dermatological disorders (skin peeling, inflammatory manifestations, keratinization abnormalities) are usually observed in this disease.
When questioned, it turns out that the formation of areas of hypopigmentation with teardrop-shaped hypomelanosis occurred without any subjective symptoms – itching or burning. Additional diagnostic criteria can be female, age over 35 years. Often, a sharp acceleration of the development of the disease occurs during the menopausal period. Histological examination is performed to differentiate teardrop-shaped hypomelanosis from certain forms of lichen and other dermatological conditions accompanied by focal destruction of melanin. The pathohistological picture in this pathology is usually characterized by unchanged skin with a reduced number or absence of melanocytes in the epidermis. An important histological confirmation of teardrop-shaped hypomelanosis is the absence of atrophic or inflammatory skin changes.
Etiotropic treatment of teardrop hypomelanosis is absent due to the ambiguity of the etiology of this condition. Intradermal injections of corticosteroids are used directly into the lesions, according to some data, this significantly slows down their growth and inhibits the development of new areas of hypopigmentation. For the same purpose, a variety of retinoid–based external agents are used – they improve pigment and general metabolism in skin tissues and, thereby, reduce the manifestations of teardrop-shaped hypomelanosis. There is no data on the possibility of completely eliminating this condition at the moment, various masking (tonal) cosmetics are used to reduce aesthetic discomfort from the presence of spots.
Prognosis and prevention
The prognosis of idiopathic guttate hypomelanosis regarding the patient’s survival is certainly favorable – this disease is not life-threatening and does not lead to serious complications. However, with regard to recovery and the return of normal pigmentation of the skin, the forecasts of specialists are more pessimistic – already developed foci of hypopigmentation can almost never be returned to their original state. At the same time, the manifestations of teardrop-shaped hypomelanosis on light, unburned skin are almost invisible, in addition, they can be masked with cosmetics. To prevent the development of this disease, people at risk (women over 30 with fair skin) should avoid prolonged exposure to the sun and visiting tanning salons. sunscreens that filter ultraviolet radiation should be used. Special care should be taken for women whose relatives have idiopathic guttate hypomelanosis – they have a much higher risk of developing this pathology due to a possible genetic predisposition.