Fungal Infections

Fungal infections are broadly divided into five types on the basis of their severity. The symptoms of these infections vary and have been listed in the appropriate sections. 

Invasive Fungal Infections
Invasive fungal infections are very dangerous and require detailed investigations for diagnosis followed by immediate medical intervention. They affect people with weak immune systems, and it is extremely rare for a person with a healthy immunity to develop this infection.
Some common invasive fungal infections are

• Candidemia and invasive candidiasis
• Intra-abdominal candidiasis 
• Cryptococcal meningitis
• Histoplasmosis disseminated
• Histoplasmosis acute pulmonary
• Invasive Aspergillosis
• Invasive rhinosinusitis
• Mucormycosis
• Pneumocystis pneumonia

Allergic Fungal Infections
Allergic fungal infections involve the respiratory system. Most allergic infections are not severe and do not have a major impact on health. Some people are prone to multiple allergies, and the presence of certain diseases tends to increase allergies. Allergic tendencies show up early in life and may disappear with age.
Some important allergic fungal infections are

• Allergic bronchopulmonary aspergillosis
• Occupational lung disease
• Severe asthma with fungal sensitization
• Thunderstorm asthma
• Allergic fungal rhinosinusitis

Chronic or Deep Tissue Fungal Infections
Deep tissue fungal infections are difficult to treat and cause long-term infection. It is believed that genetic factors may also lead to chronic fungal infections.
They usually occur due to a physical injury or due to the presence of certain diseases, such as

• Damage to the cornea of the eye (fungal keratitis)
• Fungi introduced to the subcutaneous tissue by a deep injury, such as a thorn prick or a cut
• Presence of a lung disease 

Some of the common deep tissue fungal infections are

• Chronic pulmonary aspergillosis
• Blastomycosis
• Coccidioidomycosis
• Fungal keratitis
• Fungal ball of the sinus
• Granulomatous invasive fungal rhinosinusitis
• Histoplasmosis chronic cavitary pulmonary
• Paracoccidioidomycosis

Mucosal Infections

Mucosal fungal infections generally affect the relatively less exposed surfaces of the body, such as the mouth, food pipe, and vagina. The fungus responsible for infection is Candida albicans. Most of the times, the fungi survive on mucosal surfaces without any inflammation or reactions because they survive in very low numbers on mucosal surfaces and the stomach.

Even when the fungi are present in large numbers, most people do not have a reaction, and the mucosal surfaces may get a white plaque-like coating; there may a white discharge from the vagina. Others have a severe allergic reaction to the presence of large quantities of the fungi, and reddening of the mucosa along with irritation and discomfort is observed.

Some of the common forms of mucosal candidiasis are:

• Oesophageal candidiasis
• Oral candidiasis
• Candida vaginitis
• Candida balanitis

Fungal Infections of the Skin, Hair, and Nails
These are the most common of all fungal infections and affect the skin, hair, and nails. While your body is generally capable of protecting itself from fungal infections, some fungi survive on the skin and cause infections. Symptoms vary depending on the infection but commonly lead to scaling of the skin, redness, itching, blisters, burning of skin, unusual discharges depending on the area they have infected. These fungi are of three types:

• Keratinophilic fungi
  These fungi use the protein keratin found on the skin, nails, and hair to survive.
• Candida albicans
  These fungi occur in most places and are mostly found on the bottom of babies due to irritation of diapers, in the nails, and the skin folds near the nails.
• Non-keratinophilic fungi
  These include Aspergillus spp, Alternaria alternate, and Fusarium spp. These fungi generally infect the toenails that are damaged due to an injury.

Some of the common fungal infections of this type are as follows:

• Athlete's foot
• Candida balanitis
• Chromoblastomycosis
• Mycetoma
• Onychomycosis
• Otitis externa
• Pityriasis versicolor
• Ringworm
• Seborrheic dermatitis
• Sporotrichosis
• Tinea capitis
• Tinea cruris
• Tinea manuum

Causes

Fungal infections occur when fungi come in contact with a person with decreased immunity levels, and the person’s immune system is unable to fight the infection. Fungi spores travel easily through the air and can be inhaled to cause infections. 

Risk Factors

There are certain people who are at an increased risk of fungal infections. These include:

• People with a weak immune system, such as patients with AIDS, HIV, cancer, and diabetes and the elderly and small children.
• People who are in regular contact with people experiencing fungal infections.
• People who are frequently exposed to areas that breed fungi, such as common showers and locker rooms.
• People who sweat profusely.
• People who have a genetic condition that predisposes them to fungal infections.

Fungi are present all around us and it is impossible to completely protect oneself from fungi. Most fungi are very important for our health and wellbeing. However, the prevention of recurring fungal infections of the skin, hair, and nails is possible by maintaining high standards of hygiene and avoiding places where fungi tend to breed. 

• Always keep your hands and feet clean and dry. Remember to dry your skin properly between the toes before you put on your footwear. 
• Always wear well-fitted shoes and clean dry cotton socks that allow your feet to breathe. 
• Avoid sharing items of personal hygiene such as towels, nail clippers, scissors, and combs. 
• Do not ignore fungal infections such as Athletes' foot and make sure you consult your doctor at the earliest. This helps to curb the infection in the initial stages and prevents it from spreading to your nails.

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Some fungal infections can be simply diagnosed by the signs and symptoms and do not require any tests, while others may require a biopsy. Here are some investigations that may be required: 

Dermoscopy
It is an examination of the skin using skin surface microscopy. It does not involve any punctures or application of creams/lotions or other substances. It is used to diagnose several subcutaneous fungal infections.

Laboratory Testing
Simple infections require samples of blood and urine for diagnostic purposes. Other forms of infections require samples of internal tissues. A mycological diagnosis of the sample collected helps identify the specific fungus involved in the disease and provide a specific treatment. Various tests may be prescribed based on the nature of infection considered.

Imaging
Imaging for a fungal infection is required for a complete understanding of the extent of the disease and the exact treatment required only in cases of deep fungal infections. Various imaging techniques, such as ultrasound, CT scans, and MRI scans, may be required depending upon the location and the type of infection considered.

Allergy Testing
Allergy is one of the most common fungal infections, and allergy testing helps identify the specific allergens in the environment that affect an individual. IgE is the blood test done to detect allergic reactions to fungi.

Skin Testing 
Skin testing is useful to know if an individual has been infected by an endemic fungus. A small skin sample might be collected and analyzed to look for the presence of fungi. 

All fungal infections require antifungal medication for complete cure. While some infections are minor and may increase or decrease in intensity without medication, deep fungal infections can be fatal. Treatment for fungal infections varies greatly and while most can be cured by the application of local applications, others may even require surgery. An appropriate diagnosis is necessary for accurate treatment, and no medication should be taken without the advice of a doctor.

Some common treatment options for fungal infections are as follows:

Antifungal medicines
Antifungal medicines are topical, oral, or injectable medicines depending upon the type and severity of the infection. Antifungal medicines act by destroying the cell walls of the fungi, causing the cells to die. They also act by preventing the reproduction and the growth of fungi. There is a wide variety of antifungal agents available in the market belonging to different classes, such as polyene, tubulin disrupter, azoles, allylamine, a pyrimidine analog, and echinocandin.

Corticosteroids
Corticosteroids or steroids have been used to treat diseases since the end of the 1950s. 
Some topical corticosteroids for skin are hydrocortisone, betamethasone, clobetasol, clobetasone/clobetasol, diflucortolone, and fluocinolone. 
Oral corticosteroids include prednisolone, prednisone, methylprednisolone, dexamethasone, and hydrocortisone. 
Injectable intravenous or intramuscular steroids include hydrocortisone, methylprednisolone, and dexamethasone. Inhaled corticosteroids include formulations, such as beclomethasone, fluticasone, budesonide, mometasone, and ciclesonide.

Embolisation of the Bronchial Artery
Haemoptysis, a condition wherein the patient is coughing blood, is treated through embolization of the bronchial artery in cases of a very severe fungal infection. The condition can range from mild to severe. Mild cases are treated with oral medicines, while severe cases may require hospitalization along with blood transfusion. Severe cases are difficult to treat and are often unpredictable. Rapid and frequent intervention and diagnosis are often required to control the various side-effects and prognosis of the condition.

Immunotherapy
In cases of invasive fungal infections, the immune system of the patient is severely compromised. Despite the availability of a wide range of antibiotics, death rates are very high at around 40%. Immunotherapy aims to fight invasive fungal infections by improving patients’ immune system.

• White blood cell (WBC) transfusion
  These may help to improve the immunity of the patient and help fight infection. However, the quality of WBC transfused is critical. These transfusions help control the progression of severe infections that are not easily controlled by antibiotics.
   
• Granulocyte colony-stimulating factor
  This therapy aims to stimulate the production of WBCs by the bone marrow and influences other parts of the immune system.
   
• Gamma interferon
  Gamma interferon enhances the mechanism of immune cells and makes them better destroyers of fungi.

Surgery
Surgery may be required in severe cases of fungal infections where other treatment options have failed.

Brain

• Granuloma or cyptococcoma
  Patients may need to undergo surgical removal of the infectious mass, especially if the mass is thought to be malignant. In patients who have had long periods of antifungal therapy, the organism may be in a static phase and further therapy may not help; in such cases, surgical removal is recommended.
   
• Cerebral abscess
  Stereotactic drainage or complete removal of the abscess may be required depending on the position of the abscess.

Eye

• Endophthalmitis
  A vitrectomy is advised for most cases of fungal endophthalmitis to remove the microbes and the debris.
   
• Keratitis
  ​A surgery is generally advised to treat this condition especially when deep corneal lesions are present, as more than 50% of the patients do not respond positively to antifungal therapy.

Nose

In cases of chronic sinusitis, surgery removes all allergic mucin, fungal debris, and nasal polyps and preserves the underlying mucosa.

• Fungal ball of the sinuses
  Surgical removal of the fungal ball has a high rate of curing the disease. Occasionally, an antifungal therapy may be also given to prevent local invasion.

Ear 
Fungal infections of the ear often require surgical removal of the damaged tissue right up to the bone and may result in a complete hearing loss on the infected side.

Lungs

• Invasive pulmonary aspergillosis
  An emergency surgery is often required to save the life, as the arteries are at a risk of a hemorrhage.
   
• Aspergilloma and chronic pulmonary aspergillosis
  A surgery offers a high survival rate and prevents progression of the disease and further complications.

Heart

• Pericarditis
  In case of a pericardial constriction, pericardiectomy or removal of a part of the pericardium may be required. Drainage may be initially required to control the infection after which a surgery may be conducted.
   
• Endocarditis infections
  Surgery is one of the best treatment options for this infection and is conducted as early as possible. Recovery is generally difficult after complications arise.
   
• Pacemaker and cardioverter-defibrillator wire infection: In this case, lead-extraction needs to be undertaken along with sternotomy and a cardiopulmonary bypass surgery.

Bone

• Sternal wound infection
  In this case, a surgery is conducted for debridement and for removal of wires in the infected area. The surgery is followed by an antifungal therapy.
   
• Vertebral body infection
   This infection of the bones requires a surgery to remove the debris. Bone grafting may be required depending on the condition.

Lifestyle Management

Certain lifestyles make a person more prone to environmental pathogens, including fungi. If you are frequently infected by fungal infections and the cause is related to your work, such as gardening or tattooing, then a change of occupation may provide a solution. Doctors frequently advice people with recurring allergies to relocate to places with a more suitable climate. Although lifestyle does not play a major role in fungal infections, lifestyle management might help avoid recurring allergic infections.

Prognosis

The outcome of a fungal infection depends upon various factors, such as the type and stage of infection, correct and timely treatment, and the individual response to the treatment. People with healthy immune systems generally respond favorably to treatments, while those on antibiotics or with weakened immune systems do not respond well. While most types of fungal infections are easily cured, invasive fungal infections are most difficult to cure and lead to the high mortality rates.

Complications

Fungal infections, such as candidiasis, can lead to complications if they are not treated in time. The fungi may enter the bloodstream and lead to invasive candidiasis, which can be fatal. The fungi can also travel to the other parts of your body and lead to infection in the brain, food pipe, eyes, heart, and joints. Once the infection spreads to the internal organs, cure becomes difficult and the disease is prolonged. Therefore timely diagnosis and treatment is the key to avoiding complications.

Fungi are commonly found in air, soil, and water and on plants and animals.  There are around two million species of fungi found on our planet of which around 600 are known to cause diseases.

Fungal infections affect much of the natural world and are common in both plants and animals. Humans are infected by fungi when the immune system is unable to handle the invading fungus. Sometimes, fungal infections can cause an allergic reaction on another part of the body that is not infected by the fungi at all. For example, a fungal infection on the foot may cause an allergic rash on the arms or fingers even though the arms or fingers have not come in contact with the infected area.