What Are Fungi
Fungi are simple parasitic life-forms that include mushrooms, toadstools, yeasts, and moulds. Disease-causing fungi can be divided into 2 groups: filamentous fungi and yeasts. Filamentous fungi are made up of branching threads known as hyphae, which form a network called a mycelium. Yeasts are single-celled organisms. Most fungi are either harmless or beneficial to human health, but some can cause illness and disease.
Fungal Infections are diseases that are caused by the multiplication and spread of fungi. Some fungi are harmlessly present all the time in areas of the body such as the mouth, skin, intestines, and vagina. However, they are prevented from multiplying by competition from bacteria. Other fungi are dealt with by the body’s immune system.
Fungal infections are therefore more serious in people taking long-term antibiotic drugs (which destroy the bacterial competition) and in those whose immune systems are suppressed by immunosuppressant drugs, corticosteroid drugs, or by a disorder such as AIDS. Such serious fungal infections are described as opportunistic infections. Some fungal infections are more common in people with diabetes mellitus.
Fungal infections can be classified into superficial (affecting skin, hair, nails, inside of the mouth, and genital organs); subcutaneous (beneath the skin); and deep (affecting internal organs). The main superficial infections are tinea (including ringworm and athlete’s foot) and candidiasis (thrush), both of which are common.
Subcutaneous infections, which are rare, include sporotrichosis and mycetoma. Deep infections are uncommon but can be serious and include aspergillosis, histoplasmosis, cryptococcosis, and blastomycosis. The fungal spores enter the body by inhalation.
Let us now concern ourselves with the most common of these infections namely Tinea and Candidiasis.
Tinea or Dermatophytoses commonly known as ‘ringworm’ are caused by superficial skin fungi known as dermatophytes. These live on keratinous structures and infect the epidermis (superficial layer) of skin, hair and nails. The dermatophtes responsible for human infection belong to three genera: Microsporon, Trichophyton and Epidermophyton.
The infectivity of these organisms is relatively low and prolonged contact in needed for transmission to occur. However, as mentioned earlier, this does not apply to immunosuppressed individuals and diabetics. Such patients can develop widespread infection with recurrences. Hot and humid climes favor fungal growth. As a result Tinea is more common during the summers especially if it rains. Synthetic clothes prevent sweat evaporation predisposing to fungal growth and spread.
This term is used when the infection involves the scalp. Usually it is noted in children. Well developed sebaceous glands protect the adult scalp. Scaly grey patches are classic. Rarely a boggy swelling resulting from excessive inflammation and itching can occur. This is known as ‘kerion’.
Tinea afflicts the beard areas of the facial skin.
This term refers to primary tinea surface infection of the trunk, face and extremities. Severely itchy, circular or irregular lesions with well defined borders and pigmented central areas are notable. Scaling and some erethema (reddening) is often observed.
When lesions as described above are found in the folds of the groins, inner thighs, vicinity of the penis and vagina – such are labeled as T. Cruris. Sweaty underwear, infrequent bathing, prolonged sitting and sport activity leads to the ever so blissful crotch itch!
Tinea Pedis, Mannum, Interdigitale
These are Tinea infections affecting the soles, palms and skin folds between toes and fingers. ‘Athelete’s foot’ is a common term used to describe tinea infection anywhere on the feet.
Most of the cases of cutaneous candidiasis are cause by the yeast or fungus Candida Albicans. This fungus is found as a commensal on the skin, the vagina, the mouth, and the gastrointestinal tract. Yet again heat, humidity and the immunocompromised state or diabetes or steroid therapy predispose to Candidal infection.
Candidial are chiefly red, itchy, moist and often associated with typical yogurt like odor or white yogurt resembling discharge. Satellite lesions or small areas of involvement around the main lesion are known.
It simply means Candidal involvement of the skin folds of the body in various areas such as the groins, armpits, below the breasts, between fingers/toes and under the neck.
This is candidal nail involvement. Starting at the root of the nail, the infection spreads to the nail plate proper and can often separate the nail from its bed.
Infection of the oral cavity with Candida Albicans produces a curd like white deposit associated with redness and burning sensation in localized areas of the oral mucosa. It is common in infants, children and the debilitated aged.
It is nothing but vaginal Candidal infection or vaginal yeast infection with a characteristic odor and the classic curdy white discharge. There is reddening of the labial folds with raw areas of severe itchiness. Irritation can be worsened by the fall of drops of urine onto these areas.
is the male counterpart of moniliasis with involvement of the penile glans in males and may manifest as areas of superficial red raw bruises along with curdy collection under the penile hood.
Treatment of fungal infections is with antifungal drugs, either used topically on the infected area. Topical treatment is accomplished through different delivery methods. These include Ointments, Creams for skin, Intravaginal Creams, Vaginal Pessaries or tablets. Rarely oral tablets of special antifungal agents are needed for protracted or resistant cases.
The vital factor in treating superficial fungal infections is to always remember to avoid the inciting factors as far as possible and to always treat both partners in case of genital (vaginal/penile yeast) infections.
In so far as avoiding inciting factors is concerned the following measures merit consideration as part of treatment.
- Avoid synthetic clothes especially in summers
- Bathe daily, avoid continuous stretches of sitting
- Use anti perspirant powders in socks, underwear and deodorants or sticks into skin folds
These fall under various categories as under.
ANTIBIOTICS - Nystatin (BIOSTATIN/MYCOSTATIN), Griseofulvin (FULVICIN)
AZOLES/ IMIDAZOLES - Clotrimazole, Miconazole,
SYSTEMIC AZOLES - Fluconazole (DIFLUCAN), Itraconazole (SPORANOX)
ALLYLAMINES - Terbenafine (LAMISIL)
OTHERS - Tolnaftate (ABSORBIN), Ciclopiroxolamine.
Clotrimazole Cream is the prototype imidazole anti-fungal drug. It is used topically and is available skin cream, oral lotion, vaginal cream and vaginal pessary. It is usefully also combined in creams along with topical steroids and antibiotics (QUADRIDERM –AF, BETNOVATE-GM).
Imidazoles work by inhibiting fungal cytochrome- P450 enzyme. This enzyme is vital to fungal cell survival.
Clotrimazole is efficacious in treating 60 to 100% of Tinea infection. It has greater cure rates of 80% in treating Candidal infections.
It is safe for use topically in both pregnant women and children with yeast infection.
Clotrimazole is particularly useful in curing vaginal yeast infection. It is particularly favoured for vaginits of vaginal yeast/Candidal infection as it possesses a long lasting residual effect after once daily application. This is true for vaginal Clotrimazole pessaries. Creams need twice or thrice daily applications.
The woman lies in bed on her back and inserts the pessary or applies the cream as deep as possible into the vaginal canal. Creams must be applied external to the vagina onto the vulva as well. Pessaries (ABTRIM) will dissolve and flow out from the canal painting the vulva automatically, hence the need to use a pad with a pessary. Creams do not stain the underwear.
MYCELEX Troches are lozenges which contain Clotrimazole and are designed to treat oral candidiasis or trush. They are placed in the mouth and allowed to dissolve for 15 – 30 min. They must not be chewed or swallowed. Clotrimazole mouth paints are useful for infants and children.
Clotrimazole is well tolerated by most patients. Local irritation with stinging and burning sensation may occurs in a few patients. No systemic toxicity is seen after topical use.
It is superior to Clotrimazole in treating both yeast/Candidal and Tinea infections. It has a cure rate of more than 90% for both fungi. Sharing the same minimal side effect profile, miconazole has better penetrating power into cornified tissues and is useful for Paronychia (Candidal nail bed infection) and Onychomycosis (Tinea Nail infection).
Fluconazole (DIFLUCAN) and Itraconazole (SPORANOX) have largely replaced the more toxic and interactive drug Ketoconazole in treating recurrent, resistant, Immunocompromised, Drug induced and Diabetic fungal infections.
Targeted topical therapy is the key to treating fungal skin and mucus membrane infections. One must get one’s partner treated too in cases of vaginal yeast infections, or else frustrating recurrences will result. Commensal fungi become vehement invaders in immunocompromised states like AIDS.
Nevertheless, for the rest of us, maintaining simple hygiene practices such as regular baths and washes coupled with frequent garment changes do a lot in preventing superficial fungal afflictions.