Pseudomycoses present the clinical picture of mycoses. However, unlike mycosis, pseudomycosis is not based on a fungal infection but on a bacterial infection. Therapy depends on the causative agent and the pattern of infestation but usually encompasses antibiotic administration.
What is pseudomycosis?
Mycoses are associated with microorganisms. They are fungal diseases that correspond to an infectious disease. The causative agents of the infection are mycelial fungi and yeasts. The process of infection does not necessarily lead to disease. Parasitically, the pathogens of a mycosis spread in the living tissue. The clinical picture of mycoses is relatively typical. In most cases, the infestation manifests itself in red oval or round lesions of the skin or mucous membranes, with marginal scaling and subjective association with itching or burning. Pseudomycosis presents with the clinical picture of mycosis, but is not caused by fungi. Colonization may involve the skin, lungs, or central nervous system. In most cases, pseudomycoses are reactions to bacterial pathogens of various kinds. In addition to Nocardia, actinomycetes and bacteria of the species Corynebacterium minutissimum can lead to a mycosis-like clinical picture. Especially in the case of actinomycetes, the infection often corresponds to an endogenous infection. In this case, the bacteria of the normal skin or oral flora penetrate into deeper tissue layers. In extreme cases, pseudomycoses can cause bacteremia and associated sepsis. Depending on the pathogen, symptoms and the predominantly affected tissue differ.
Causes
Depending on its cause, pseudomycosis is divided into several subgroups. Infections with Nocardia and, in particular, the bacterium Nocardia asteroides cause the so-called nocardiosis, which manifests as pseuomycosis in the central nervous system and lungs. Another causative agent of pseudomycoses are bacterial actinomycetes, which can cause a so-called actinomycosis or radiation mycosis and manifest as pseudomycosis of various body regions. Actinomycoses are divided into cervico-facial, thoracic and intestinal forms depending on the tissue affected and thus the course. Actinomycetes in particular resemble the shape of fungi in their morphology and for this very reason are often referred to as ray fungi. The most common pathogen of these pseudomycoses is the species Actinomyces israelii, which naturally inhabits the human mouth as a commensal. Infections with Corynebacterium minutissimum, which inhabits the normal skin flora and causes predominantly mycosis-like skin symptoms. With this cause, pseudomycosis is also known as erythrasma. The common feature of all pseudomycoses is their bacterial origin, which is considered the ultimate criterion for differentiation from true mycoses. In general, immunocompromised or otherwise immunodeficient patients are most at risk for pseudomycosis.
Symptoms, complaints, and signs
Patients with nocardiosis present with symptoms of granulomatous infectious disease and are often affected by pneumonia, brain abscess, endocarditis, or empyema. Actinomycoses are also associated with abscess formation. The pus collections of bacteria and dead cells spread to surrounding tissues, and the dermal consistent lesions are framed by connective tissue and granulation tissue. In addition to the skin, these pseudomycoses can affect the lungs, chest area, abdominal organs and mucous membranes, central nervous system, or face, neck, and mouth areas. Erythrasma typically manifests itself again in the form of skin symptoms, which appear as sharply demarcated, brownish-red, flat areas of skin with fine wrinkles and scales. This pseudomycosis in particular can be accompanied by itching. Most often, this variant occurs in the armpits, in the inguinal region, on the scrotum or in the spaces between the toes, with the infection spreading to other regions of the skin. All bacterial infections may be accompanied by general signs of infection such as fatigue, tiredness, fever, and chills. If there is central nervous system involvement, functional impairment of sensibility or motor function may present. If the bacteria reach the bloodstream, patients with a poor immune system may develop blood poisoning.
Diagnosis and course of the disease
The diagnosis of pseudomycosis is usually established by cultural detection of the typical pathogens. However, this detection takes some time, especially in the case of actinomyces, so that microscopic view must often serve as a diagnostic criterion. Involvement of organs and mucous membranes is further assessed by imaging techniques. The prognosis of patients varies with the type of pathogen and the pattern of involvement. A life-threatening situation may be present with sepsis. Untreated nocardiosis is usually fatal. Erythrasma is associated with the best chance of cure.
Complications
In severe cases, pseudomycoses can cause bacteremia and, as a result, sepsis. In bacteremia, bacteria invade the bloodstream. The pathogens are usually easily destroyed by the immune system in healthy adults. However, in children whose immune system is not yet fully developed, as well as in seniors and adults with weakened immune systems, the elimination of the pathogens is not always successful. These then reach the organs via the bloodstream and infect them. The result can be severe blood poisoning or septic shock, which leads to circulatory collapse. Both sepsis and the shock it causes can be fatal for the patient. Chronic erythrasma may develop in diabetics. This is a form of pseudomycosis that spreads in the body and fat folds of overweight individuals, with diabetics being particularly frequently affected. The infection is manifested by scaly, brownish skin lesions that may emit an unpleasant odor if left untreated. Treatment with antibiotics is usually successful, but in some patients the disease does not heal. Erythrasma either does not resolve completely or recurs at short intervals.
When should you see a doctor?
The typical skin changes indicate pseudomycosis, which must be examined by a doctor in any case. If scaly or horny areas of skin are noticed in the groin, armpit, or scrotum that hardly itch, a visit to the doctor is recommended. Patients at risk include those with obesity, diabetes mellitus, hyperhidrosis and immunosuppression. Affected individuals should call the doctor if the above symptoms appear and do not resolve on their own within a week or even increase in intensity. Pseudomycosis is treated by the family doctor or a dermatologist. In addition, the symptoms can be taken to an internist. If the condition has a very negative effect on well-being, therapeutic counseling may be useful to accompany the medical treatment. The patient should discuss the necessary measures with the physician and, if necessary, involve other medical professionals in the treatment. Children should be presented to the pediatrician if the reported symptoms occur and do not resolve on their own.
Treatment and therapy
The causative agent determines the treatment of pseudomycosis. Nocardioses are treated with antibiotics such as ceftriaxone in combined administration with aminoglycoside. For actinomycoses, antibiotic administration in the form of aminopenicillin or tetracycline treatment is sufficient in the early stages, with surgical intervention to open abscesses required in the advanced stages of disease. Erythrasma is usually treated locally with miconazole and fusidic acid cream. Benzoic acid and ASA may also be given. Systemic therapy with erythromycin usually lasts two weeks and is associated with optimal cure rates. Single-dose therapy with clarithromycin is also within the realm of possibility for this variant of pseudomycosis. In some circumstances, photodynamic therapy is an alternative to pharmacologic treatment. This treatment uses red light and is usually combined with draining the involved skin areas with moisture-absorbing powders and air-permeable clothing. In cases of pseudomycosis involving the central nervous system, functional impairment may persist even after healing, and this is usually countered with physiotherapeutic measures.
Prevention
Because pseudomycosis due to actinomyces in particular often occurs during dental surgery, prophylactic antibiotics are often administered before and after major dental surgery.In addition, because pseudomycosis specifically affects immunodeficient patients, strengthening the immune system is considered a preventive step.
Follow-up
Pseudomycosis is caused by bacteria. Therefore, the treating physician will usually prescribe an antibiotic. Here, the unconditional assistance of the patient is required. The antibiotic must be taken regularly and for a certain period of time so that it can develop its full effect. If the medication is discontinued too early, complications or relapses may occur. Diabetics and people with severe obesity often have delayed wound healing. Sores in body folds often heal with great difficulty. Treatment with red light is recommended here. Corresponding devices can be obtained relatively inexpensively from the trade. The irradiation with red light dries out the affected skin areas and thus strengthens the healing process. Medicated powders also help to absorb moisture. To avoid unnecessary sweating, loose, airy clothing made of natural materials should be worn during the infection. As with all infectious diseases, it is important to strengthen and stabilize the immune system. A diet rich in vitamins, exercise in the fresh air and moderate sporting activity accelerate the healing process. A strengthened immune system helps especially older people and people with a general immune deficiency to cope more quickly with pseudomycosis.
What you can do yourself
Since pseudomycosis is caused by bacteria, the attending physician usually prescribes an antibiotic. Here, good “compliance” is important, which means that the patient should absolutely follow the doctor’s instructions and take the prescribed antibiotic regularly. This is the only way to ensure the success of the treatment. The medication must also not be discontinued prematurely under any circumstances, as otherwise relapses or complications may occur. In diabetics or people who are overweight, the sore areas may not heal. These are usually areas in skin or body folds. Here, additional treatments with red light devices are recommended, as they can be bought cheaply everywhere. Red light baths dry the affected skin areas, which contributes to faster healing. This effect can be enhanced with powders that absorb moisture. It is also advisable to wear natural, air-permeable clothing so that the affected areas of the body do not sweat unnecessarily. A fresh diet rich in vitamins, a regular daily routine and plenty of fresh air contribute to stabilizing the immune system and thus to healing. This also applies to regular exercise and moderate sports. Elderly people or people with a general immune deficiency especially benefit from an improved immune system, because otherwise pseudomycosis may not heal completely in them.
