Fungal infections of the skin are a common condition caused by the overgrowth of fungi. These microorganisms normally live on the skin, but when they find suitable conditions (warmth, moisture), they can multiply and cause inflammation.

Types of Skin Fungal Infections

Depending on the type of fungus and the affected area, a fungal infection can be classified as:

  • Dermatophytosis (Ringworm): Caused by dermatophytes, it affects the keratin layer of the skin, nails, and hair. Depending on the location, it is called:
    • “Athlete’s foot” (tinea pedis).
    • Body ringworm (appears as circular lesions with central clearing).
    • Scalp ringworm (tinea capitis).
    • Jock itch (tinea cruris).
  • Candidiasis: Caused by the yeast Candida, it mainly affects moist areas such as skin folds, genitals, and nails.
  • Pityriasis Versicolor: Caused by the yeast Malassezia, it appears as light or dark spots, usually on the trunk and upper limbs.

Symptoms

The most common symptoms of a fungal infection include:

  • Itching.
  • Redness and rash.
  • Peeling of the skin.
  • A burning sensation.
  • Unpleasant smell (especially on the feet).
  • Thickening or discoloration of the nails (onychomycosis).

Risk Factors

  • High temperature and humidity.
  • Sweating.
  • Tight clothing and shoes.
  • Immunosuppressive conditions (e.g., diabetes, steroid use, chemotherapy).
  • Sharing towels or other personal items.

Treatment

The treatment for a fungal infection is effective and depends on the type and severity of the infection.

  • Topical Treatment: For superficial infections, the dermatologist will prescribe antifungal creams, sprays, or lotions.
  • Systemic Treatment: In more severe or widespread cases, as well as with nail or scalp infections, oral antifungal medications may be required.
  • Prevention: Keeping the skin dry and maintaining good hygiene are important for preventing recurrence.

NAIL FUNGAL INFECTIONS (ONYCHOMYCOSIS)

Onychomycosis accounts for 15-40% of all nail diseases.

Predisposing Factors

  • Age >50 years.
  • Vascular disorders of the lower limbs, lymphοedema.
  • Smoking.
  • Frequent trauma (athletes) and tight shoes.
  • Psoriatic onychia.
  • Hyperhydrosis (excessive sweating).
  • Orthopedic conditions.
  • Diabetes mellitus.
  • Immunosuppression.
  • Skin fungal infections (athlete’s foot).

Clinical Appearance

This is determined by how the fungus enters and the extent of its colonization. Based on these, the following clinical types arise:

  • Distal Subungual Onychomycosis: This is the most common type. The infection starts at the free edge and sides of the nail and spreads towards the root. It is most commonly caused by dermatophytes (Tr. rubrum, Tr. interdigitale). It is characterized by thickening (hyperkeratosis), yellowing, and separation of the nail (onycholysis).
  • White Superficial Onychomycosis: This is a rare form that affects only the surface of the toenail. It is caused (90%) by Tr. interdigitale. Small, white, opaque spots appear, which grow and cover the entire surface.
  • Proximal Subungual Onychomycosis: This type is less common and usually appears in individuals with a weakened immune system and is typically caused by Tr. rubrum. The infection enters from the skin near the nail root and spreads outward. It can result from trauma or paronychia, and colonization by Candida albicans and bacteria gives the nail’s side surface a characteristic greenish hue.
  • Endonyx Onychomycosis: The responsible fungus (dermatophyte) invades the nail plate, causing lamellar splitting and leukonychia.
  • Total Dystrophic Onychomycosis: This is the final stage of any of the above forms if not treated properly. The entire nail is completely destroyed, becoming thick, brittle, and can detach.
  • Mixed Type Onychomycosis: A combination of the above on the same or different nails.
  • Secondary Onychomycosis: The appearance of a fungal infection on a nail that is already pathological due to trauma or psoriasis/lichen planus.

Diagnosis

To confirm the diagnosis, the dermatologist usually follows these steps:

  • Clinical Examination: The doctor carefully examines the affected nail and the skin around it, often using a dermatoscope (onychoscopy) to identify characteristic lesions.
  • Sample Collection: A small sample (scraping) is taken from the affected area of the nail.
  • Laboratory Testing: The sample is sent to the lab for:
    • Direct Microscopy: This is a quick test where the sample is examined under a microscope for immediate fungal detection.
    • Culture: The sample is placed in a special nutrient medium, allowing the fungi to grow. This process usually takes 2-4 weeks and allows for the precise identification of the fungal species. Identification is crucial, as it determines the appropriate treatment.

It is very important that no topical or systemic antifungal treatment has been used for a specific period before the sample is taken, so as not to affect the reliability of the results.

Treatment

The treatment of onychomycosis is a process that requires patience and persistence, as complete healing can take several months. The choice of treatment depends on the type and extent of the infection and is always done under the guidance of a dermatologist.

The main treatment methods include:

  • Topical Treatment: Used in mild cases when the infection has not spread to a large part of the nail or the matrix and for maintenance or prevention after systemic treatment. It involves the use of special antifungal varnishes, creams, or lotions, which are applied directly to the nail.
  • Systemic Treatment: Indicated for more extensive and resistant cases where the infection has reached the nail matrix. The doctor prescribes oral antifungal medications (pills), which act from the inside out. This treatment can also be combined with topical treatment for better results.
  • Laser Therapy: A newer, painless method that uses a laser (e.g., Nd:YAG) to destroy the fungus with heat. It is often combined with topical treatment and is considered a safe option, especially for patients who cannot or do not want to take oral medications. Its effectiveness is high, but several sessions are usually required.
  • Surgical Debridement: In special cases, the dermatologist may proceed with the mechanical removal of the affected nail to allow for better drug action or when they consider that no other treatment will be effective.

Fungal Infections in Children

In children, onychomycosis is a rare disease, and due to the rapid growth of the nail and the thin nail plate, it is treated with topical therapy. It is recommended to check the skin for a possible fungal infection and to diagnose and treat other family members.

Recurrence

Onychomycosis is characterized by frequent recurrences (10-53%) due to re-emergence or re-infection, which is why it is important to follow preventive measures to avoid the reappearance of the infection, such as:

  • Keeping feet dry (using absorbent powder and cotton socks) and ensuring good ventilation.
  • Avoiding walking barefoot in public places (hotels and gyms).
  • Simultaneous treatment of all affected family members.
  • Avoiding trauma.
  • Using sterilized tools for nail care.

Important Note: For a correct diagnosis and treatment, it is essential to visit a dermatologist. Self-diagnosis and the use of treatments without medical advice can worsen the condition.