Histoplasmosis is an infection with the mold Histoplasma capsulatum, which can affect the entire body but is usually confined to the lungs. In Europe, this disease is rare. Areas of distribution are especially Africa, Indonesia, South, Central and partly North America.
What is histoplasmosis?
The causative agent of histoplasmosis is a dimorphic fungus called Histoplasma capsulatum. Dimorphic means that it can occur both in the mycelial form as a mold and in the single cell form as a yeast. Its appearance depends on the temperature. The mold form is present at 25 degrees and the yeast form is present at 37 degrees (body temperature). With appropriate exposure to this fungus, anyone can contract histoplasmosis, although immunocompromised individuals usually do not develop symptoms. Only in immunocompromised individuals, such as those with AIDS, does the pathogen frequently spread throughout the body with an often fatal course of the disease. In the areas where this fungus spreads, histoplasmosis is considered a defining symptom of HIV.
Causes
Histoplasmosis is causally caused by infection with the fungus Histoplasma capsulatum. Infection often occurs in bat burrows or chicken coops. It is transmitted by dust and settles in the lungs. Immediately, the so-called macrophages (scavenger cells) become active and surround the fungal cell. However, the fungus is not killed during this phase. On the contrary, it can continue to multiply within the scavenger cells by sprouting. Since it appears at body temperature in the form of a single cell as a yeast fungus, it can thus enter the entire body with the macrophages via the bloodstream. In persons with an intact immune system, the pathogens are killed in a further phase of the immune reaction. Thus, in over 90 percent of cases, no symptoms occur and lifelong immune protection against Histoplasma capsulatum is established. Immunocompromised individuals, on the other hand, often develop severe courses of disease with histoplasmosis, some of which are fatal.
Symptoms, complaints, and signs
In about 90 percent of cases, infection with Histoplasma capsulatum does not cause any symptoms. In isolated cases, small scars in the area of the lungs may be detected during x-ray examination. Symptomatic patients suffer from complaints such as dry cough, weakness and general cold symptoms. In addition, severe stomach pain with vomiting may occur. During the course of the disease, fever and chills also occur, along with attacks of sweating and severe stomach pain. Initial symptoms usually occur within 3 to 14 days after contact with the fungus. If histoplasmosis progresses further, weight loss may develop. In addition, symptoms such as weakness, shortness of breath, and chest pain may occur. If the eyes are involved, visual disturbances occur. A severe course is manifested by patchy areas in the lower part of the lungs. In people with weakened immune systems, other symptoms may occur. Corresponding risk groups suffer from headaches, cramps and injuries in the oral cavity accompanying the histoplasmosis symptoms. In the absence of treatment or inadequate treatment, infection with Histplasma capsulatum can lead to the death of the patient. Depending on the form of the disease, other symptoms of the brain, nervous system, or skin may occur.
Diagnosis and course
Because of the rarity of histoplasmosis in Europe, misdiagnosis is common. Although the disease is usually silent, infection with a high concentration of fungal spores or immunodeficiency can lead to severe symptoms characterized by pain on inhalation, fever, chills, and cough. There may also be a bloody cough, wart-like lumps on the skin, and swollen lymph nodes. A tentative diagnosis is made by surveying the circumstances of the illness and ruling out diagnoses of other diseases. If the suspicion of histoplasmosis is confirmed, the fungus Histoplasma capsulatum can be detected by skin swabs, biopsy of the lungs, and blood or spinal cord tests. Imaging techniques show shadows on the lungs produced by calcific nodules. Antibody detections are usually unreliable in histoplasmosis because immunocompromised individuals in particular do not show adequate immune responses.
Complications
Histoplasmosis causes severe symptoms and complications in the lungs and respiratory tract. In most cases, the affected person initially feels ill and fatigued and suffers from severe fever. Furthermore, pneumonia and a dry cough occur. The cough may also develop into hemoptysis, which can usually lead to anxiety or panic attacks. The patient’s immune system is severely weakened and further infections or inflammations may occur. Furthermore, the usual symptoms of influenza also occur, so that the patient’s resilience drops extremely. There is also underweight and in many cases dehydration. The patient’s quality of life is greatly reduced and limited by histoplasmosis. Direct treatment is not necessary in every case. Often histoplasmosis heals on its own and no further complications occur. If the patient has previously suffered from a weakened immune system, treatment is carried out with the help of medication. If left untreated, histoplasmosis can lead to death in the worst case if the affected person also has HIV, for example.
When should you go to the doctor?
If the affected person suffers from impaired breathing, a doctor should be consulted. If there are no other colds or allergic reactions, respiratory restrictions are considered worrisome and must be clarified. This leads to an undersupply of the organism, which in the long run leads to a life-threatening condition. In case of inner restlessness, a feeling of illness or general weakness, a doctor should be consulted. Fatigue, exhaustion and a drop in usual performance are signs that must be thoroughly examined and treated. If the symptoms increase or spread further in the body, a visit to the doctor is essential. If the affected person suffers from pain when breathing in, special caution is required. With this warning, a visit to the doctor should be made as soon as possible so that no further damage occurs. Sleep disturbances, palpitations, high blood pressure and abnormalities of the heart rhythm should be examined by a physician. Swollen lymph nodes that are not related to influenza are considered unusual, especially if they are present for several weeks. Signs such as chills and severe unwanted weight loss also require a visit to the doctor. A slow increase in the symptoms described are indications of fungal disease. The affected person experiences a gradual deterioration in his or her well-being and should seek medical attention as soon as the changes lead to restrictions in his or her daily obligations.
Treatment and therapy
Therapy for histoplasmosis is usually not necessary because of the mild symptoms. Individuals with an intact immune system may also experience acute symptoms as a result of infection with a high concentration of the pathogen, but the disease heals completely after seven to eighteen days. Immunocompromised individuals, on the other hand, often develop the chronic form of histoplasmosis, in which the pathogens are not completely destroyed. Chronic histoplasmosis can then progress to the disseminated form with severe symptoms, leading to death in over 90 percent of cases if left untreated. However, if disseminated histoplasmosis is treated, the lives of over 85 percent of patients can be saved. In the chronic or disseminated course of the disease, it is imperative to treat with antifungal drugs (antifungal agents) for several weeks. If foci of pus have formed in the body, its surgical removal is indicated. Persons with chronically weakened immune system (HIV) must be permanently treated with antifungal drugs in case of histoplasmosis.
Outlook and prognosis
The prognosis for histoplasmosis is tied to the patient’s overall health. If the immune system is stable and healthy, the prognosis is favorable. The pathogens can be killed by the body’s own defense system. As a result, spreading is prevented and the fungal spores are removed from the organism via the person’s natural excretory system. In addition, the body develops immunity to the pathogens, so that the affected person is adequately protected against a renewed infestation of fungal spores for life.People who have a weakened immune system can expect a worse prognosis in most cases. The risk group includes infants, children, elderly people or chronically ill people. In them, the body’s immune system is not yet fully developed or is not functional due to other disorders. As a result, it is difficult or impossible to kill the pathogens. In addition, they can multiply and spread further without any significant resistance. If comprehensive medical care is not provided, the general state of health of the affected person deteriorates within a short time. In addition, further diseases can develop, since the organism is basically susceptible to germs, bacteria or other fungi. The prospect of a cure for these people depends on the progress of the disease as well as the possibility of providing sufficient support for the immune system.
Prevention
To prevent histoplasmosis, mouth guards should be worn in a high-risk area, such as when visiting a bat cave. Individuals with weakened immune systems can prophylactically inhale antifungals or take certain antibiotics. Even healthy individuals who have already built up immunity to histoplasmosis should not expose themselves to the pathogens in massive amounts.
Follow-up
In most cases, there are no special and direct options and measures of aftercare available to those affected by histoplasmosis. In this regard, this disease must be primarily examined and treated by a physician to prevent further complications or further worsening of symptoms. Histoplasmosis can only be treated by early detection of the symptoms. The disease can lead to death if left untreated. In most cases, drugs are used to treat histoplasmosis. Care must be taken to ensure that the medication is taken regularly and, above all, correctly. In case of any uncertainties or questions, a doctor should always be consulted first. Possible drug interactions or side effects should also be taken into account. Likewise, the lungs must be spared in histoplasmosis. Efforts or stressful and physical activities should be avoided in order to avoid unnecessary strain on the lungs. Smoking should also be avoided, although a healthy lifestyle can generally have a very positive effect on the further course of this disease. Contact with other sufferers of histoplasmosis can also be useful in this regard, as it is not uncommon for information to be exchanged.
What you can do yourself
Histoplasmosis can be prevented by strict hygiene measures. If the affected person is in a risk area during this process, a mouth guard must be worn, for example. In general, the disease can be avoided by avoiding exposure to the agents that cause histoplasmosis. If the patient suffers from a weakened immune system, antibiotics can be taken as a precaution to prevent an outbreak of the disease. However, if the disease is serious, treatment by a physician is always necessary, otherwise the disease can lead to the death of the patient. Patients must take care of their bodies during treatment and not subject them to unnecessary stress. Bed rest is recommended, and the affected person should be cared for by friends or relatives. In case of pneumonia, various home remedies such as teas or milk with honey can be used to spare the throat and counteract the cough. In case of panic attacks or anxiety, a conversation with a doctor should always be sought. Usually, the doctor can reassure the patient and explain the consequences of the disease. Talking to other histoplasmosis patients can also have a positive effect on the disease.
