Erythrasma is a chronic pseudomycosis of bacterial origin that affects the epidermis mainly in places of large skin folds. Disease is manifested by the appearance and fusion of painless gray-brown, brown-red or yellowish-brown spots covered with fine peeling. Diagnosis is based on its clinical picture, localization of foci, typical luminescence during luminescence examination, characteristic microscopic picture. Disinfection of underwear and clothing is of no small importance in the treatment. Treatment of lesions, antibiotic therapy, UV irradiation, correction of blood sugar, hyperhidrosis therapy is carried out.
Erythrasma got its name due to the reddish glow of lesions during luminescent diagnostics. Translated from Greek, the word “erythrasma” means “red staining”. The disease occurs mainly in adults, more often among males and is characterized by a long course without any negative subjective feelings.
For a long time, disease was considered a fungal skin disease. This was due to the fact that microscopy of scales taken from erythrasma-affected areas of the skin revealed the presence of sinuous thin filaments resembling mycelium of a fungus. In modern dermatology, erythrasma is referred to pseudomycosis — diseases similar in clinical picture to a fungal lesion of the skin, but having a completely different etiology.
The causative agent of erythrasma Corynebacterium minutissimum belongs to Corynebacteria. It has low pathogenicity and low contagiousness and is normally found on the skin surface of healthy people as a saprophytic microorganism. Transmission of infection occurs by contact through personal hygiene items, during sexual contact, visiting a bath or pool, while walking barefoot on the ground or on the beach.
The causative agent affects only the surface layer of the skin (epidermis), hair and nails remain intact. The penetration of bacteria into the epidermis with the development of this disease can contribute to:
- hyperhidrosis and changes in the pH of the skin to the alkaline side;
- hot and humid climate;
- friction and maceration of the skin (traumatic dermatitis), diaper rash;
- individual characteristics of the macroorganism;
- poor skin hygiene or, on the contrary, too frequent washing with soap, violating the natural protective properties of the skin.
Erythrasma begins with the appearance on the surface of the skin of rounded non-inflammatory spots of light brown, brick-red, brownish or yellow-brown color. The diameter of the spots may be small or reach several centimeters. Spots with erythrasma often have rounded edges, but may also be scalloped. Increasing in size, the lesions begin to merge forming a single large area of erythrasma, clearly delimited from healthy skin. It has a smooth surface and is covered with small bran-like scales. Over time, brown pigmentation or paling of color is noted in the central part of the area affected by erythrasma.
The characteristic localization is the skin of large folds. In men, most often there is a lesion of the inguinal region, the inner surface of the thighs, as well as the skin around the anus. In women, erythrasma more often occurs in the folds under the mammary glands, on the skin of the umbilical and axillary areas. In overweight people, it is possible to defeat the folds on the abdomen.
Usually disease is not accompanied by any subjective sensations. Only in some cases, patients notice a slight itching. Because of this, erythrasma can go unnoticed for a long time and not serve as a reason for contacting a dermatologist. Erythrasma proceeds for a long time (more than 10 years) and is accompanied by alternating periods of remission and exacerbation. Exacerbations of erythrasma usually occur in the summer, when warm weather contributes to a greater proliferation of bacteria.
In patients with obesity, hyperhidrosis, diabetes mellitus, erythrasma can take a complicated course with the addition of eczema symptoms, the appearance of diaper rash or secondary infection of the lesion. The development of complications is also facilitated by friction, increased humidity and contamination of the affected area of the skin with erythrasma. Complicated erythrasma is characterized by the appearance of burning, itching and /or soreness in the affected area.
Erythrasma can be diagnosed by its typical clinic and the location of the affected areas, a characteristic red-coral or red-brick glow during a fluorescent study with a Wood lamp. Luminescent diagnostics should be carried out on an untreated area of erythrasma, since washing or treatment can wash away the pigment secreted by bacteria. Microscopy of a scrape taken from an erythrasma-affected area of the skin reveals mycelium-like sinuous filaments and coccoid cells forming chains or separate groups.
Differentiate erythrasma from inguinal epidermophytia, multicolored lichen, rubromycosis, pink lichen, skin candidiasis, microbial eczema, perianal dermatitis. In difficult cases, to exclude other diseases, scraping is carried out on nutrient media to identify the pathogen. Determination of the sensitivity of the pathogen to antibacterial drugs is necessary when choosing a drug for systemic antibiotic therapy.
To prevent self-infection and successful treatment of erythrasma, it is necessary to disinfect clothes, shoes, personal items and bed linen of the patient. Clothes and underwear should be washed daily and ironed. In the complex treatment of erythrasma in patients with diabetes mellitus, an endocrinologist’s consultation is necessary to correct blood sugar levels.
Local treatment of erythrasma consists in rubbing erythromycin or sulfur-tar ointment in the affected area. The procedure is carried out 2 times a day for a week. After that, the erythrasma spots persist for some time, and then gradually fade and disappear. When a secondary infection is attached and inflammatory changes appear in the lesions, they are additionally treated with resorcinol alcohol or aniline dyes. A large area of lesions in erythrasma is an indication for systemic antibiotic therapy.
The drying and disinfecting effect of soft ultraviolet rays favors the speedy resolution of erythrasma foci and prevents the occurrence of exacerbations of the disease. Therefore, it is useful for patients to be in the sun in the morning and evening hours, as well as undergo local UFO procedures.
Patients with excessive sweating during erythrasma remission should receive effective treatment of hyperhidrosis: sympathectomy, ultrasound destruction, curettage or surgical excision of the sweat glands of the problem area.
Primary prevention of erythrasma includes skin hygiene, thorough drying of the skin in large folds after a shower or bath, refusal to wear too tight clothes and underwear made of synthetic fabrics, the fight against excess weight and excessive sweating (deodorants, antiperspirants, botulinum toxin mesotherapy).
Secondary prevention, aimed at preventing recurrence of erythrasma, is carried out within a month after the disappearance of symptoms of the disease and consists in the treatment of skin folds with camphor or salicylic alcohol, followed by the application of talc.