Muscarinic Syndrome: Causes, Symptoms & Treatment

Muscarinic syndrome is a type of mushroom poisoning. In this case, the symptoms typical of muscarinic syndrome appear a few minutes after consuming the mushrooms in question. These include both vegetative and neurological symptoms that indicate impairment of the autonomic nervous system. Muscarinic syndrome may lead to death and for this reason poses a great danger, especially to mushroom pickers.

What is muscarinic syndrome?

The very name of the syndrome indicates that the substance muscarinic is the responsible toxin. Muscarinic is a so-called parasympathomimetic that strongly resembles acetylcholine in structure. For this reason, the substance is able to bind to the same receptor of the parasympathetic nervous system. The corresponding receptors are also called muscarinic acetylcholine receptors. The difference and the cause of the symptoms, however, is that the so-called acetylcholinesterase is unable to break down muscarinic. As a result, permanent irritation of the parasympathetic nervous system occurs, resulting in the typical and sometimes life-threatening symptoms of muscarinic syndrome. The substance muscarinic was scientifically proven for the first time in fly agaric mushrooms in 1869. Since fly agarics cause similar neurological symptoms, researchers long assumed that fly agarics could also cause muscarinic syndrome. However, it was later discovered that other toxins are present in fly agarics, namely muscimol and ibutenic acid. However, the concentration of muscarinic is much too low in fly agaric to cause poisoning such as muscarinic syndrome. On average, the content of muscarinic acid in fly agaric mushrooms is about 200 times lower than in the responsible species of crack mushrooms. The symptoms of muscarinic syndrome appear rapidly after consumption of the mushrooms. In many cases, they occur within minutes of their consumption, but no later than three hours.

Causes

The cause of muscarinic syndrome is due to the substance of the same name, which is found in some types of mushrooms. In the majority of cases, these are small funnel mushrooms, which are usually white in color. Some crack mushrooms also cause muscarinic syndrome. In contrast, the fly agaric contains only traces of the toxin muscarinic, although it was named after this substance. For mushroom pickers, the risk arises primarily when clove swallows are collected. For here there is a slight risk of confusion with funnel mushrooms. Collecting May mushrooms is also problematic, as they are sometimes confused with brick-red crack mushrooms. Rauschpilze are in some cases confused with the Erdblättrigen Risspilz, which also contains muscarine.

Symptoms, complaints, and signs

Muscarinic syndrome presents with many different symptoms and complaints that are typical of poisoning. In most cases, the first symptoms appear a few minutes after eating the mushrooms and at the latest after two to three hours. Thus, immediately after the mushroom meal, there is an increased production of saliva and lacrimation coupled with sweating, vomiting and nausea. In addition, visual disturbances and shortness of breath often occur, while the pulse slows. These symptoms are extremely unpleasant for the affected individuals and sometimes result in serious complications. However, there is an antidote with good efficacy. This is atropine, the poison of belladonna. If this antidote is administered quickly, the symptoms of muscarinic syndrome disappear within a few minutes. If the antidote is not immediately available, there is a risk of death from cardiovascular failure. Because muscarinic acts similarly to neurotoxins, it affects the autonomic nervous system. In doing so, it affects the parasympathetic nervous system, which is why muscarinic syndrome is accompanied by corresponding symptoms. These include, for example, visual disturbances, as the pupils become severely constricted (miosis). In addition, increased sweat is produced (hyperhidrosis). Gastrointestinal tract complaints such as nausea and vomiting become apparent. Muscarinic syndrome is often accompanied by tremor and a slow pulse. In some cases, blood pressure drops sharply. Breathing becomes difficult as the airways narrow. In addition, many patients become panicky.

Diagnosis and course of the disease

Because muscarinic syndrome is a potentially life-threatening poisoning, treatment is indicated as soon as the syndrome is suspected. If symptoms appear after a mushroom meal, therapy should be initiated immediately. The substance muscarinic can be detected in the serum by a laboratory test. The diagnosis can be confirmed by examination of the mushrooms eaten or the vomit. If the antidote atropine is applied quickly, the chances of survival are relatively good.

Complications

Muscarinic syndrome can cause death of the patient in the worst case scenario. For this reason, serious poisoning must be investigated by a physician in all cases. Without treatment, serious consequential damage to the internal organs of the affected person can also occur. In most cases, muscarinic syndrome causes patients to suffer from the complaints and symptoms of typical poisoning. There is nausea, vomiting and furthermore also fever or sweating. The resilience of the affected person decreases and there are disturbances in coordination or concentration. Also visual disturbances can occur by the Muskarin syndrome and furthermore with a shortness of breath are connected. Due to the shortness of breath, the affected person may also suffer a loss of consciousness. In many cases, death continues to occur due to heart failure. Affected individuals suffer from tremors and a severely slowed pulse. Treatment of muscarinic syndrome must be acute in all cases. In doing so, the death of the affected person can be avoided. In some cases, the poisoning can also damage the internal organs. Whether this results in a reduction in life expectancy cannot be generally predicted.

When should you see a doctor?

If health disorders occur immediately after eating mushrooms, a doctor should be consulted. If there is nausea, vomiting, a malaise or diarrhea, there is an impairment of the organism. If the symptoms persist or increase in intensity, a visit to the doctor should be made. Sweating, dizziness, a sharp increase in salivation, and tremors indicate an irregularity that should be investigated and treated. Paralysis, muscle disturbances, or a sharp drop in circulation should be presented to a physician. A constriction of the pupils, an elevated body temperature, and internal weakness are signs of an irregularity. Since muscarinic syndrome can lead to premature death of the affected person in severe cases, a doctor should be consulted in time. If an acute condition occurs, an ambulance should be alerted. In the event of a collapse of the cardiovascular system or loss of consciousness, immediate action is required. First aid measures must be initiated until the arrival of the emergency physician. If the affected person suffers from reduced vision as well as shortness of breath, a doctor is required. Medical assistance must also be sought as soon as the symptoms occur during or after a visit to a restaurant and no explicit mushroom dish has been consumed. Cooks may have used the mushrooms chopped up as a flavor enhancer or seasoning to the menu without the knowledge of the affected person.

Treatment and therapy

To treat muscarinic syndrome, first induce vomiting of the meal in the affected person, if possible. Gastric lavage may be necessary. Subsequently, 20 to 40 grams of activated charcoal are administered several times each. It is particularly important that the patient be provided with sufficient fluids. The antidote atropine is usually administered intravenously. Therapy is accompanied by ECG monitoring.

Outlook and prognosis

In muscarine poisoning, the prognosis depends primarily on the amount of the substance consumed, the patient’s constitution, and the promptness and comprehensiveness of intervention. Immediate action should be taken even if consumption of a muscarinic mushroom is suspected. These include vomiting and gastric lavage as well as the administration of activated charcoal to resorb the toxin. If the symptoms of poisoning are very severe, atropine may need to be administered as an antagonist. If such measures are omitted, severe muscarinic intoxication may result in death from cardiac or respiratory arrest. If treatment is initiated in a timely manner, symptoms of poisoning can almost always be terminated within 24 hours. Permanent damage is not to be expected.Mild muscarinic poisoning is treated with gastric lavage and administration of activated charcoal and is often overcome within 2-4 hours. If the first gastric lavage takes place within one hour after mushroom consumption, this is usually sufficient as a treatment measure. Mild poisoning usually ends after two hours even without medical treatment. However, since it can never be reliably estimated in advance how severe a poisoning will ultimately be, a doctor should be consulted immediately in any suspected case.

Prevention

Because muscarinic syndrome is a threatening fungal poisoning, preventive measures and knowledge are of high importance for mushroom pickers. If there is uncertainty about the nature of a mushroom, refrain from eating it. Ambiguities in mushroom picking can be resolved, for example, with experienced mushroom connoisseurs.

Aftercare

Affected persons have either no or very few measures of direct aftercare available in most cases of muscarinic syndrome. With this disease, a physician must be consulted at a very early stage to prevent further complications or other medical conditions from developing. If left untreated, the disease leads to the death of the patient. Such poisoning is a serious disease, which must be treated by a doctor in any case. Even at the first signs and symptoms, affected persons should consult a doctor. Furthermore, in the case of muscarinic syndrome, the intake of the respective mushrooms should be interrupted in order not to poison the body even further. This may include gastric lavage. After such a procedure it is recommended to rest and recover. It is necessary to refrain from exertion or other stressful or physical activities. Likewise, only light food should be taken so as not to overload the stomach. In many cases, those affected by muscarinic syndrome are also dependent on the help and care of their own family. If the disease is recognized and treated in time, there are usually no further complications and also no reduced life expectancy of the affected person.

What you can do yourself

When signs of muscarinic syndrome are noticed, vomiting must be induced in the affected person immediately. An emergency physician must then be called or the affected person must be taken immediately to a hospital, where gastric lavage and drug treatment can be administered. After the initial treatment, the sufferer should initially take it easy. The diet must be changed in the first few days after the poisoning. In order not to put additional strain on the stomach, mainly light foods and lean meat should be eaten. Irritating foods and stimulants should be avoided for the time being. In addition, the medication prescribed by the doctor must be taken to prevent a relapse. If unusual symptoms are noticed, the doctor in charge must be informed immediately. After a few days, the symptoms should have subsided. Further self-help measures are limited to taking care of the body and especially the gastrointestinal tract. In addition, more caution should be exercised when picking mushrooms in the future. If there is uncertainty about the nature of the mushrooms collected, they should not be eaten. The already collected poisonous mushrooms must be disposed of in any case.