What is eosinophilic pneumonia?
Eosinophilic pneumonia is a group of very different lung diseases in which doctors can detect an increased number of a certain type of white blood cell (leukocytes) in the lungs and sometimes also in the blood. This form of white blood cells are eosinophilic granulocytes, also known as eosinophils or “Eos” for short. These blood cells are an important part of the immune system and are particularly involved in allergic reactions, inflammatory reactions and the fight against parasites and viruses.
Eosinophil granulocytes make up around one to four percent of all white blood cells. The name “eosinophilic” comes from the fact that the blood cells can be stained in the laboratory with the dye eosin. They then appear pink or reddish under the microscope.
Eosinophilic pneumonia – acute or chronic
Eosinophilic pneumonia occurs in two variants: Acute and chronic. What both have in common, however, is that eosinophil granulocytes migrate into the lung tissue. The symptoms can be very different. They range from mild to life-threatening. Acute eosinophilic pneumonia progresses rapidly, whereas the chronic form develops slowly over weeks or months. Without treatment, both forms can seriously endanger health.
Eosinophilic pneumonia – clinical pictures with many faces
There are various, often very different clinical pictures that fall under the term “eosinophilic pneumonia” – depending on the cause. Löffler’s syndrome (simple eosinophilic pneumonia) is one example. It causes symptoms in the respiratory tract, often a dry cough. Acute and chronic eosinophilic pneumonia and tropical eosinophilic pneumonia (presumably a hypersensitivity to the tropical nematodes Wuchereria bancrofti and Brugia malayi) are also included.
In addition, eosinophilic pneumonia can also occur as part of another disease that affects not only the lungs but the whole body. One example is eosinophilic granulomatosis with polyangiitis (formerly Churg-Strauss syndrome). In this very rare disease, the small and medium-sized blood vessels become inflamed and eosinophil granulocytes migrate into the tissue. Hypereosinophilic syndrome also falls into this group. Large quantities of eosinophils are present in the blood over a longer period of time (more than six months).
Eosinophilic pneumonia – frequency and age
There are no precise figures on the incidence of eosinophilic pneumonia. But overall they are rare diseases. Chronic idiopathic eosinophilic pneumonia usually occurs in middle age (age 30 to 39), but can in principle occur at any age. Even children can contract the disease, albeit very rarely. It affects women about twice as often as men. Many also suffer from an allergy, such as bronchial asthma or allergic rhinitis.
Acute idiopathic eosinophilic pneumonia is rarer than the chronic variant. However, men seem to be affected slightly more often than women. On average, sufferers are around 29 years old, but acute lung disease can occur at any age. Most patients are not asthmatics, but some are smokers.
Eosinophilic pneumonia: causes are often unclear
In many cases, the causes of eosinophilic pneumonia cannot be traced. “Idiopathic” is the medical term for when the causes of the disease remain unknown. However, specialists are also aware of some causes that are involved in the development of eosinophilic pneumonia. These include, for example:
- Smoking (young men who smoke cigarettes often develop the acute form)
- Infections with parasites (especially worms), molds (mostly Aspergillus fumigatus) or bacteria
- Medication, e.g. antibiotics (penicillins, sulphonamides, isoniazid, nitrofurantoin), anticonvulsants for epilepsy (e.g. carbamazepine, phenytoin), painkillers (non-steroidal anti-inflammatory drugs = NASAR such as naproxen, ibuprofen, diclofenac), sulphonylureas for diabetes (e.g. chlorpropamide) – there are many other medications that could be a possible cause
- Chemical vapors, such as nickel
- Other diseases, for example eosinophilic granulomatosis with polyangiitis (formerly Churg-Strauss syndrome)
Symptoms: Eosinophilic pneumonia can be mild or severe
Eosinophilic pneumonia can be acute or chronic. The severity of the symptoms also often varies from person to person. Some experience mild symptoms, while others develop life-threatening conditions that we then have to treat immediately.
Acute eosinophilic pneumonia – symptoms
This form of lung disease progresses rapidly and can cause the following symptoms:
- Fever
- Chest pain – it intensifies when the affected person takes a deep breath
- Shortness of breath, shortness of breath
- Cough
- Muscle pain
- General feeling of illness
- A sharp drop in the oxygen content in the blood (hypoxemia) – respiratory failure can develop within hours or days.
Löffler syndrome – Symptoms
Löffler’s syndrome usually only causes mild respiratory symptoms, sometimes it also progresses without symptoms. The following signs indicate Löffler syndrome:
- Dry cough (without sputum)
- Panting
- Shortness of breath, shortness of breath
- Fever
- Tiredness, fatigue, malaise
The affected person usually recovers quickly. After a few days, but at the latest after two to three weeks, the symptoms subside.
Chronic eosinophilic pneumonia – symptoms
Chronic eosinophilic pneumonia usually begins insidiously. The symptoms slowly intensify over days or weeks. Like the acute form of this lung disease, it can be very dangerous for those affected. The following signs may occur:
- Fever
- Chills
- Night sweats
- Cough
- Loss of appetite and weight loss
Those affected often also suffer from an allergic disease – with the corresponding symptoms. Around 30 percent also have bronchial asthma.
The chronic form often returns on its own (relapse or recurrence) and then worsens over weeks or months. Without treatment, those affected can develop shortness of breath, which can be life-threatening.
Diagnosis: Eosinophilic pneumonia
The diagnosis of eosinophilic pneumonia begins with a discussion with us about your medical history (anamnesis).
The following questions, for example, may be of interest:
- What symptoms do you experience exactly and since when?
- How severe would you describe your symptoms?
- Do you smoke? If yes: Since when and how much?
- Do you have any known illnesses, for example infections or other underlying diseases?
- Have you recently traveled abroad? If so, where to?
- Are you exposed to chemical vapors in your everyday life or at work?
- Are you taking any medications? If yes: Which and since when? (e.g. antibiotics, painkillers?)
Based on your answers, we can already draw initial conclusions about the cause of your symptoms. This is usually followed by a physical examination. For example, we listen to the lungs and listen for noises when breathing in and out that are not normal. These diagnostic methods are also used, among others:
- X-ray examination of the chest: Radiologists can often detect (migrating) infiltrates on both sides as well as opacities (like frosted glass) or densification.
- Computed tomography (CT) of the lungs: CT allows the airways and changes in the lung parenchyma to be visualized. As the examination is carried out both inhaling and exhaling, regional differences in ventilation can be detected at an early stage. In addition, eosinophilic pneumonia shows typical changes in the lungs.
- Lung endoscopy (bronchoscopy): We advance a flexible instrument (endoscope) into the trachea and bronchi via the mouth or nose, which is equipped with a camera and light source. This allows the lungs and their fine branches to be examined. At the same time, we can remove fluid during bronchoscopy using bronchoalveolar lavage (BAL), and sometimes also take a tissue sample (biopsy). This is then analyzed.
- Blood test: We take a blood sample and a laboratory determines the amount of eosinophil granulocytes in the blood. In addition, various other blood values may be altered (IgE antibodies elevated or “p-ANCA” detectable). Indications of existing infections with fungi or parasites can also be read from the blood.
- Stool sample: Worms and parasites can often be detected in the stool.
Eosinophilic pneumonia: prevention, early detection, prognosis
The causes of eosinophilic pneumonia remain unknown in many cases. Therefore, there are no special measures for the prevention and early detection of eosinophilic pneumonia. In general: Always visit us promptly if you have respiratory problems and other symptoms. However, some factors are considered to be co-triggers of eosinophilic pneumonia and you can sometimes tackle these yourself and possibly prevent the lung disease. Some tips:
- Good hygiene protects against infection with parasites and other “pathogens”. Find out about possible risks of infection at your destination and – if possible – take preventive measures in good time. This is especially true if you are traveling to countries with poor hygiene conditions. The most important thing is to wash your hands regularly and thoroughly!
- Don’t smoke – and if you are a smoker, try to stop smoking.
- If you come into contact with chemical vapors in everyday life and at work – take adequate protective measures.
- Some medications cause eosinophilic pneumonia as a side effect, for example painkillers. Always discuss with us whether and which medicines you really need. Do not take such medication on your own over a long period of time.
Course and prognosis of eosinophilic pneumonia
Eosinophilic pneumonia can take very different courses. Mild courses are known in which the symptoms quickly improve again (even without therapy). However, severe courses can also occur. Without timely diagnosis and treatment, both acute and chronic eosinophilic pneumonia can be life-threatening. If treatment is started quickly, the prognosis is usually good.
Sometimes those affected also need medication over a longer period of time to keep the pneumonia in check. This is because the chronic form of the disease tends to recur on its own (relapse or recurrence).
Eosinophilic pneumonia: treatment with medication
Eosinophilic pneumonia can be treated effectively with medication. High doses of glucocorticoids are used in both acute and chronic forms. One example is the active ingredient prednisone. Both variants of the lung disease respond quickly and well to the anti-inflammatory medication. The symptoms usually improve quickly. They are therefore the drugs of first choice.
In the acute form of the disease, patients occasionally recover without therapy. A characteristic of acute eosinophilic pneumonia is that it usually does not recur. Patients with chronic eosinophilic pneumonia may have to continue treatment with glucocorticoids for several months or even years. This is because the disease often returns of its own accord.
Depending on the cause, the following treatment strategies can also help:
- Medicines that alleviate the symptoms, such as wheezing and shortness of breath
- Medication if worms or other parasites are the cause of the disease
- Discontinue medication if drugs trigger eosinophilic pneumonia. We are looking for alternative medications that are better tolerated.
- Treat underlying diseases, for example eosinophilic granulomatosis with polyangiitis
- Treat concomitant diseases, for example bronchial asthma
