Zygomycosis (Entomophthoromycosis): Causes, Symptoms, and Treatment

What is Zygomycosis (Entomophthoromycosis)?

Zygomycosis, also known as entomophthoromycosis, is a rare but serious fungal infection caused by fungi belonging to the class Zygomycetes or the order Entomophthorales. These fungi are commonly found in soil, decaying organic matter, and some foods. While most people are exposed to these fungi without developing an infection, individuals with weakened immune systems or certain underlying health conditions are at higher risk.

The infection can affect various parts of the body, including the skin, sinuses, lungs, and, in severe cases, the brain. There are two main types of zygomycosis:

• Rhinocerebral zygomycosis: Affects the sinuses, nose, and brain.
• Cutaneous zygomycosis: Affects the skin, often following a break in the skin like a burn or wound.
• Pulmonary zygomycosis: Affects the lungs, usually after inhaling fungal spores.
• Gastrointestinal zygomycosis: Affects the digestive system, often seen in severely malnourished individuals.
• Disseminated zygomycosis: Spreads through the bloodstream to other organs, including the brain.

Entomophthoromycosis specifically refers to infections caused by fungi in the order Entomophthorales, which typically cause chronic subcutaneous (under the skin) infections. These infections are more common in tropical and subtropical regions.

Sources: CDC, Mayo Clinic

Common Causes

Zygomycosis is caused by exposure to fungal spores from the environment. However, not everyone exposed to these fungi will develop an infection. The following conditions or factors increase the risk of developing zygomycosis:

• Weakened immune system: Individuals with conditions like HIV/AIDS, cancer, or those undergoing chemotherapy or organ transplantation are at higher risk due to suppressed immune function.
• Uncontrolled diabetes: High blood sugar levels can impair the immune system's ability to fight off infections, particularly diabetic ketoacidosis, which is a significant risk factor.
• Long-term corticosteroid use: Prolonged use of steroids can weaken the immune system and increase susceptibility to fungal infections.
• Severe burns or wounds: Open wounds, especially large or contaminated ones, provide an entry point for fungal spores.
• Malnutrition: Poor nutrition weakens the body's defenses, making it easier for infections to take hold.
• Intravenous drug use: Sharing needles or using non-sterile equipment can introduce fungi directly into the bloodstream.
• Trauma or surgery: Injuries or surgical procedures, especially those involving contaminated materials, can increase the risk.
• Iron overload (hemochromatosis): Excess iron in the body can promote fungal growth.
• Prematurity or low birth weight: Newborns, especially those with underdeveloped immune systems, are at higher risk.
• Environmental exposure: Living or working in areas with high levels of decaying organic matter, such as farms or construction sites, increases exposure to fungal spores.

Sources: NIH, WHO

Associated Symptoms

The symptoms of zygomycosis depend on the type and location of the infection. Here are the common symptoms associated with each type:

Rhinocerebral Zygomycosis

• Facial swelling or pain, often on one side
• Headache or sinus pain
• Fever
• Black, necrotic (dead) tissue in the nasal passages or palate
• Vision changes or loss of vision
• Confusion or altered mental status (if the infection spreads to the brain)

Cutaneous Zygomycosis

• Redness, swelling, or warmth at the site of infection
• Pain or tenderness
• Ulcers or blisters that may ooze fluid
• Black, necrotic tissue (in severe cases)
• Slow-healing wounds

Pulmonary Zygomycosis

• Cough, sometimes with blood (hemoptysis)
• Fever or chills
• Shortness of breath or chest pain
• Fatigue or weakness
• Weight loss

Gastrointestinal Zygomycosis

• Abdominal pain or swelling
• Nausea or vomiting
• Diarrhea or bloody stools
• Loss of appetite
• Weight loss

Disseminated Zygomycosis

• Fever or chills
• Fatigue or weakness
• Organ failure (depending on which organs are affected)
• Septic shock (in severe cases)

Entomophthoromycosis (Subcutaneous)

• Slow-growing, painless nodules or lumps under the skin
• Swelling or hardness in the affected area
• Ulceration or drainage from the nodules
• Mild itching or discomfort

Sources: Cleveland Clinic, MSD Manuals

When to See a Doctor

Zygomycosis is a serious infection that requires prompt medical attention. You should see a doctor if you experience any of the following:

• Persistent fever, especially if you have a weakened immune system
• Unexplained facial swelling, pain, or black tissue in the nose or mouth
• Wounds that do not heal or show signs of infection (redness, swelling, pus)
• Coughing up blood or persistent chest pain
• Abdominal pain with nausea, vomiting, or bloody stools
• Lumps or nodules under the skin that grow or become painful
• Vision changes or headaches, especially if you have diabetes or a weakened immune system

Early diagnosis and treatment are critical to preventing complications, such as the spread of infection to the brain or other organs.

Diagnosis

Diagnosing zygomycosis involves a combination of clinical evaluation, imaging, and laboratory tests. Here’s how doctors typically diagnose the infection:

Medical History and Physical Exam

Your doctor will ask about your symptoms, medical history, and any risk factors (e.g., diabetes, immune suppression, recent injuries). A physical exam will focus on signs of infection, such as skin lesions, facial swelling, or respiratory symptoms.

Laboratory Tests

• Tissue biopsy: A small sample of infected tissue is taken and examined under a microscope for fungal elements. This is the gold standard for diagnosis.
• Cultures: The tissue sample may be cultured in a lab to identify the specific fungus causing the infection.
• Blood tests: While blood tests cannot diagnose zygomycosis directly, they can check for signs of infection (e.g., elevated white blood cell count) or underlying conditions like diabetes.

Imaging Studies

• CT scan or MRI: These imaging tests help assess the extent of the infection, especially in cases of rhinocerebral or pulmonary zygomycosis.
• X-rays: May be used to evaluate lung infections.

Molecular Tests

In some cases, PCR (polymerase chain reaction) tests may be used to detect fungal DNA in tissue samples, providing a faster and more accurate diagnosis.

Sources: UpToDate, NIH

Treatment Options

Treatment for zygomycosis depends on the severity and location of the infection. It often requires a combination of medical therapies and, in some cases, surgery.

Medical Treatments

• Antifungal medications: The primary treatment for zygomycosis is intravenous (IV) antifungal drugs, such as:
  • Amphotericin B (first-line treatment)
  • Posaconazole or isavuconazole (used in some cases, especially for maintenance therapy)
  These medications are often given for several weeks or months, depending on the response to treatment.
• Management of underlying conditions: Controlling diabetes, improving nutrition, or adjusting immunosuppressive medications can help the body fight the infection.
• Hyperbaric oxygen therapy (HBOT): In some cases, HBOT may be used as an adjunct therapy to improve oxygen delivery to infected tissues and enhance the effectiveness of antifungal drugs.

Surgical Treatments

Surgery is often necessary to remove infected or necrotic (dead) tissue, especially in cases of rhinocerebral or cutaneous zygomycosis. Surgical options include:

• Debridement (removal of infected tissue)
• Sinuses or nasal passage surgery (for rhinocerebral infections)
• Amputation (in severe cases of limb infections)

Home Care and Supportive Treatments

While medical treatment is essential, the following supportive measures can help manage symptoms and improve recovery:

• Wound care: Keep wounds clean and dry to prevent further infection. Follow your doctor’s instructions for dressing changes.
• Pain management: Over-the-counter pain relievers (e.g., acetaminophen or ibuprofen) may help with mild pain. Prescription medications may be needed for severe pain.
• Nutritional support: A balanced diet rich in vitamins and minerals can support immune function. In severe cases, nutritional supplements or IV nutrition may be necessary.
• Hydration: Drink plenty of fluids to stay hydrated, especially if you have a fever or are taking medications.
• Rest: Adequate rest helps the body recover from infection.

Sources: CDC, Mayo Clinic

Prevention Tips

Preventing zygomycosis involves reducing exposure to fungal spores and managing underlying health conditions. Here are some practical tips:

• Control diabetes: Keep blood sugar levels within the target range to reduce the risk of infection.
• Boost immune health: Eat a balanced diet, exercise regularly, and get enough sleep to support your immune system.
• Practice good hygiene: Wash hands frequently, especially after handling soil, decaying matter, or animals.
• Protect wounds: Clean and cover cuts, burns, or scrapes to prevent fungal spores from entering the body.
• Use protective gear: If you work in environments with high fungal exposure (e.g., farming, construction), wear gloves, masks, and long sleeves.
• Avoid contaminated materials: Be cautious with compost, decaying wood, or old buildings where fungal spores may be present.
• Manage chronic conditions: Work with your healthcare provider to control conditions like HIV, cancer, or autoimmune diseases that weaken the immune system.
• Avoid intravenous drug use: If you use IV drugs, seek help to quit and use sterile needles if you cannot stop.
• Regular check-ups: If you are at high risk (e.g., immunosuppressed), regular medical visits can help catch infections early.

Sources: WHO, CDC

Emergency Warning Signs

Zygomycosis can become life-threatening if not treated promptly. Seek immediate medical attention if you experience any of the following emergency warning signs:

• High fever with confusion or altered mental status: This could indicate the infection has spread to the brain.
• Severe headache with vision changes or loss: A sign of rhinocerebral zygomycosis spreading to the brain or eyes.
• Black or necrotic tissue in the nose, mouth, or skin: Indicates advanced tissue damage that requires urgent treatment.
• Difficulty breathing or chest pain with coughing up blood: Suggests a severe lung infection or spread to the bloodstream.
• Severe abdominal pain with vomiting blood or bloody stools: Could indicate gastrointestinal zygomycosis with complications.
• Signs of septic shock: Such as very low blood pressure, rapid heartbeat, cold or clammy skin, or extreme weakness. This is a medical emergency.
• Spread of infection to multiple organs: Symptoms like jaundice (yellow skin), severe fatigue, or organ failure require immediate care.

If you or someone else exhibits these symptoms, call emergency services or go to the nearest emergency room immediately. Delaying treatment can lead to permanent damage or death.

Sources: NIH, Cleveland Clinic