Yellow nail syndrome is a valuable diagnostic sign of various pathological processes that pose a threat to the patient’s health. Such a change in color is possible with jaundice, lymphostasis, endocrine disorders, lung, heart and skin diseases. The change in the color of the nail plate is accompanied by its thickening, roughness, deformation. Visual diagnosis of yellow nail syndrome is not difficult, in order to clarify the nature of the pathological process, it is necessary to take a scrape for fungi, conduct a biopsy of a part of the nail plate, examine the patient in order to identify somatic pathology. Treatment consists in eliminating the cause of the disease.
Yellow nail syndrome is a rare pathology, most often becoming the first sign of disorders in the lymphatic system (lymphedema), latent tumors and jaundice of various genesis. It can be caused by other somatic diseases and dermatoses. Yellow nails indicate the presence of pleural effusion in pulmonary pathology, the syndrome develops with AIDS and as a result of prolonged use of certain medications. Sometimes the disease is of a family nature, pigmentation of the nail plate is initially inherent in some nationalities.
Yellow nail syndrome has no gender component, occurs with the same frequency in women and men. Age-related features are that in the vast majority of cases, pathology affects patients older than 50 years. The syndrome does not have seasonality and endemicity. The urgency of the problem is connected with the diagnostic value of disorders, as well as with the fact that any change in nails reduces the psychological comfort of patients, violates their quality of life.
The vast majority of dermatologists believe that the pathological process of changing the color of nail plates is associated with hereditary and autoimmune disorders provoked by tumor processes in the liver, gallbladder or bile ducts, which result in a violation of bile outflow and obstructive jaundice. Another cause of yellow nail syndrome is called a violation of lymph outflow, as a result of which lymphostasis develops, as well as peripheral circulatory disorders. Other conditions that lead to the appearance of yellow nail coloration are well known: onychomycosis, psoriasis, onychodystrophy, smoking, nail injuries, the use of toxic lacquers and drug allergies.
The mechanism of changing the color of the nail plate is associated with the concentration of bile pigments, melanin and hemosiderin in the subcutaneous space. Bile pigments accumulate in the nail as a result of general disorders. Hemoglobin is constantly disintegrating in the body, while iron is reused, and heme is converted into bilirubin. Free bilirubin circulates in the blood, bound to proteins. In this form, it enters the liver, where protein is disconnected from it, and the pigment itself is captured by hepatocytes, combines with hyaluronic acid, becomes unfree (water-soluble) and is excreted in urine and feces, staining them yellow and brown. With tumor processes in the liver, gallbladder and biliary tract, there is an obstacle to the free movement of bilirubin from the liver to the intestine. In the state associated with hyaluronic acid, it is forced back into the blood, its level increases, the pigment accumulates in the subcutaneous space, changing the color of the nail.
Local hemosiderosis is the result of extravascular destruction of red blood cells. The output of blood cells outside the vascular bed is provided by autoimmune processes that occur in the body with systemic diseases (lung pathology, tumors, HIV), injuries, and the toxic effect of certain substances. Due to the impaired permeability of the vascular wall, erythrocytes enter the connective and epithelial tissue of the dermis, are destroyed, lose hemoglobin and become the starting material for the formation of hemosiderin, which accumulates in epithelial cells and regional lymph nodes. Part of the cells is destroyed, the pigment is released, impregnating collagen and elastic fibers with iron. Most likely, the localization of the pathological process is due to a violation of peripheral blood circulation.
Lymphostasis develops in a similar way. Only with it, lymph leaves the lymphatic vessels, disrupting the lymph flow in the distal phalanges of the fingers, impregnating the sub-elbow space and changing the color of the nail. This development of the process is associated with the mutating FOXC2 gene, which transmits a hereditary predisposition to yellow nail syndrome. The formation of melanin accumulations is explained by a violation of the normal functioning of keratinocytes as a result of dystrophic changes in the dermis. Keratinocytes themselves do not synthesize melanin, they receive pigment from melanocytes – cells of the epidermis that protect the skin from harmful environmental factors, including UVI. When UV triggers act on the skin, active synthesis of melanin occurs and its transfer to keratinocytes, which carry excess melanin to the surface of the skin. Localization of melanin in the subarticular space is associated with the place of penetration of the pathological principle into the body.
The change in the color of nails with mycosis depends on the type of fungus that caused the pathological process. Rubromycosis and favus stain the nail yellow. The syndrome is also caused by medications such as resorcinol, akrikhin, and carotene. Smoking leads to a change in color due to the tobacco resins contained in the cigarette, the systematic use of coffee – due to the pigments that make up the drink. Pathology of the digestive tract, dysbiosis provokes yellowing of nails due to impaired absorption of products containing vitamins A, E, D. Carotene causes carotenodermia, the deposition of carotene in the epidermis. Any yellowness of the nails is a signal of trouble in the body and requires a detailed examination by specialists.
In modern dermatology there is no generally accepted classification of this pathological process. From the point of view of practicing dermatologists, it is rational to divide the disease, depending on clinical manifestations, into the following groups:
- Yellow nail syndrome as a result of pathology of the lymphatic system. It is characterized by the fact that it may precede lymphedema – edema of the limb and periarticular roller or be a secondary manifestation of lymphostasis. Symptoms increase over several years, the nail loses its ability to grow.
- Yellow nail syndrome as a result of diseases of internal organs (obstructive jaundice, pathology of the pulmonary system, oncological processes, cardiac pathology), is accompanied by a slowdown in the growth of the nail plate with the disappearance of the eponychium and lunule.
- Yellow nail syndrome as a result of onychodystrophy, characterized by thinning of the nail, its deformation, delamination.
- Yellow nail syndrome as a result of systemic dermatoses is accompanied by the appearance of special “marks” on the nail plate: thimble indentations, longitudinal and transverse dashes, hyperkeratosis.
- Yellow nail syndrome as a result of onychomycosis, is characterized by thickening of the nail plate, its turbidity, looseness, subcutaneous hyperkeratosis, lesion of the periarticular roller.
- Yellow nail syndrome as a result of injuries, accompanied by a violation of the connection of the nail with the matrix, a change in its shape, structure, surface.
- Yellow nail syndrome as a result of drug intoxication is characterized by hyperkeratosis, thickening of the nail plate with a change in its shape and various shades of color: from pale yellow to orange.
- Yellow nail syndrome as a result of smoking, excessive coffee consumption, is accompanied by a change not only of the nail plate, but also of the fingers themselves.
- Yellow nail syndrome as a result of disruption of the digestive system with the development of carotenodermia or Balti symptom, is characterized by fragility of the nail plate, staining of palms and soles in orange-yellow color.
Each clinical type of pathology has its own characteristics, but there are also common signs of yellow nail syndrome. The process begins with a change in the thickness of the nail plate, then it turns yellow, the nails acquire a convex shape, lose luster, become rough, sometimes slow down growth, begin to crumble and layer. Circumflex rollers are rarely involved. Yellow nail syndrome is always combined with concomitant pathology, even in the case of discoloration as a result of the toxic effect of cosmetic lacquers, changes occur in the skin with visual manifestations of the allergic process. It is important that in some cases, nail syndrome is the first sign of a latent systemic or oncological process and requires the intervention of specialists.
Diagnosis and treatment
There is no special diagnostic algorithm, a dermatologist makes a clinical diagnosis based on the symptoms and a detailed examination of the patient in order to identify concomitant pathology. It is mandatory to exclude mycosis (scraping and sowing on mushrooms), biochemical blood analysis and lymphography. An oncologist’s consultation is scheduled. Pathology is differentiated with psoriasis, onychodystrophy, onychomycosis, pachionychia. Therapy is symptomatic, long-term, depends on the cause of the development of yellow nail syndrome. Correction of concomitant pathology is necessary. The effect of external and internal use of vitamin E with zinc supplements, diuretics, antifungal drugs was noted. The prognosis depends on the causes of the syndrome.