MYCETOMA / MADURA FOOT

This is a chronic localised infection which can be caused by various
species of fungi (eumycetoma) and bacteria, actinomycetes and nocardia
(actinomycetoma). These micro-organisms live in the soil and enter the
skin usually after a penetrating injury. The most common localisation is
therefore the foot or lower leg in barefoot persons but lesions may
appear anywhere on the body. A painless subcutaneous nodule or
induration is followed by more nodules which may discharge pus with
grains (small hard pinhead sized particles) through fistules, form abscesses
and ulcers and spread to underlying bones and joints. The colour and
hardness of the grain may help in deciding on the causative agent.
Management of mycetoma
- Smaller lesions which can be surgically removed without causing disability should
be radically excised.
- Decide on fungal or bacterial origin before installing drug therapy. Direct microscopy
(in 20% potassium hydroxide) of pus containing grains may help: after the grains are
crushed eumycetomas show hyphae, actinomycetomas small slender filaments.
Culture allows final identification. When in doubt, refer.
- Eumycetoma (caused by fungi) are virtually untreatable: antifungals e.g.
itraconazole, fluconazole, ketaconazole, miconazole, and griseofulvin have a success
rate of less than 30%. Actinomycetoma (caused by bacteria): dapsone or
cotrimoxazole combined with streptomycin. Streptomycin can be substituted by
amikacin, sulfonamides by rifampicin.
- Drug therapy often fails. Radical surgery / amputation is then the only option.

CANDIDIASIS

Candida is a resident yeast of the mucous membranes. It becomes
pathogenic under favourable host conditions. These are:
- When host immunity is decreased such as in HIV-infected and cancer
patients or by systemic steroids, cytotoxic drugs, and radiotherapy.
- Pregnancy and contraceptive pill use.
- Warmth and moisture (babies’ nappy area, groins, under breasts,
between toes).
- Use of broad-spectrum antibiotics which kill resident non-pathogenic
bacteria.
- Diabetes mellitus.
Candidiasis or thrush presents on the skin as red macules often with
small pustules on their periphery which break down as the lesion spreads
outwards. On the oral and vulvo-vaginal mucosa redness, superficial
erosions and white adherent plaques may be seen. These can be itchy
and painful. When oral lesions extend to the throat and oesophagus they
can cause anorexia. Infection of lips / corners of the mouth also occurs.
Severe mucosal candidiasis is seen often in HIV infection.
Management of candidiasis
- Treat large oozing lesions with potassium permanganate dressings
or baths for 10 minutes twice daily. Keep lesional skin dry.
- Paint mucosal or smaller wet lesions with Gentian Violet
solution once daily until healed. Application on normal skin
or on large areas is very unsightly.
- Nystatin ointment or cream twice daily for skin, nystatin
oral suspension (1 ml) swirled around mouth four times daily
until two days after clinical cure for oral candidiasis, nystatin
pessaries nightly for 2 weeks for vaginal candidiasis.
- An imidazole cream twice daily for skin infections,
miconazole oral gel 5 ml 4 times daily for 1 week for oral
thrush, imidazole pessaries 1-3 nights for vaginal thrush.
- Nappy rash: apply an imidazole cream and cover with
zinkoxide cream or ointment.
- In severe cases e.g. oesophageal thrush ketaconazole
200 mg twice daily for 1-2 weeks or itraconazole 100 mg
once daily for 2 weeks or fluconazole 50-200 mg once daily
for 1-2 weeks.
- Treatment duration may need to be extended in
immunocompromised patients.
- Griseofulvin is not an effective treatment
for candida infections.

PITYRIASIS VERSICOLOR

This is a common, chronic, superficial fungal infection which is caused by
the yeast pityrosporum. It is usually asymptomatic, causing only cosmetic
complaints. Pityrosporum is a normal skin resident predominantly of
seborrhoeic areas which becomes pathogenic under favourable circumstances:
warmth and humidity, pregnancy, serious underlying disease or
a genetic predisposition. On the scalp the infection presents as dandruff,
from there the neck and upper trunk become infected. Recurrences are
common, especially after inadequate treatment or re-infection.
Management of pityriasis versicolor
- Scrubbing the skin with a brush takes away a lot of the infected scales.
- Do not use vaseline, olive oil or palm oil.
- An imidazole cream twice daily on affected areas for 4 weeks. Add selenium
sulphide shampoo or ketaconazole 2% shampoo (expensive) twice weekly for the
scalp if lesions are widespread or if they are recurrences or
- Selenium sulphide suspension (e.g. Selsun shampoo) to affected areas overnight as a lotion or
- Selenium sulphide suspension (e.g. Selsun shampoo) to affected areas and the scalp
for 10 minutes daily for 2-4 weeks or
- Sodiumthiosulphate 20% solution overnight for
2-4 weeks or
- Propylene glycol 50% in water applied twice daily to
affected areas + scalp for 2-4 weeks or
- Salicylic acid 5% + sulphur 5% ointment
overnight for 2-4 weeks or
- Salicylic acid 5% gel or lotion overnight for
2-4 weeks.
- Recurrences can be prevented by 2 weekly or
once monthly preventiive treatment with any
of the above.
- In severe recurrent cases: ketaconazole 400 mg
stat or ketaconazole 200 mg once daily for 5 days
or itraconazole 200 mg once daily for 1 week.
- Treatment is complete when all the scales have
disappeared. You can test this by stretching
affected skin between two fingers; if scales
appear the infection is still active. After treatment
hypopigmentation may persist for some time and
wil re-pigment faster when exposed to the sun.

ATHLETE’S FOOT

Itchy, often macerated whitish scaling lesions and inflammation of the
skin in the interdigital spaces of the foot. Most common between the 4th
and 5th toe. The condition is not always caused by fungi but can be
caused by bacteria as well. For this reason oral antifungals are often
ineffective. The condition is often seen in people wearing rubber boots or
rubber / plastic sandshoes.
Management of Athlete’s foot
- Keep the space in-between the toes DRY. This may be achieved by drying the
skin thoroughly after washing, exposing to air, using betadine scrub, GV paint,
wearing cotton socks and not wearing shoes that are too tight or hot. Changing
socks daily will help prevent re-infection.
- An imidazole cream or Whitfield’s ointment twice daily until a week after symptoms
have cleared. This usually takes a minimum of 4 weeks.

TINEA UNGUIUM

Fungal infection of the nails is common, especially of the toenails in the
elderly, where it generally does not require treatment. There may be a
mixed fungal and yeast infection of toenails and /or fingernails.
Chronic paronychia is a chronic inflammation of the skin around the nail
caused by mixed or yeast infections. It often occurs in people who frequently
wet their hands such as domestic workers, cleaners, kitchen and
laundry staff.
Management of tinea unguium
Infection of the toenails:
- Usually this does not require any treatment. Thickened toenails may be softened using
Whitfield’s ointment or urea 10 to 40% ointment, and then thinned with a stone or a file.
- Systemic treatment of infected toenails is sometimes indicated e.g. when there is
pain or when the patient is young; griseofulvin 500 mg once daily until the affected
nails have grown out completely, this may take a year or longer. Recurrences are
common, take this into account when deciding whether to use one of the more
expensive drugs as listed below for infection of the fingernails.
Infection of the fingernails:
- Griseofulvin 500 mg once daily in adults or griseofulvin 10 mg/kg once daily in
children. Continue treatment until the affected nails have grown out completely,
this may take 4-9 months.
- If there is no improvement after 2-4
months, there may be a mixed infection
(griseofulvin treats only fungal infections,
not yeast infections) or resistance to
griseofulvin. One of the systemic azoles
should be given, e.g. ketaconazole 200 mg
once daily until symptoms clear or
itraconazole 200 mg once daily for
3 months or itraconazole 200 mg twice
daily for 1 week per month during
3 months. Alternative: terbinafine 250 mg
once daily for 6-16 weeks.
Chronic paronychia: Keep dry! Work
conditions may need adapting. Bathe in
betadine or potassium permanganate
solution followed by application of an
imidazole cream or GV paint twice daily.
Massaging the nailfold with a mild steroid
helps decrease swelling.
Fig. 24. Fungal infection
of the hand and nails.

TINEA CAPITIS

Scalp ringworm is common in children. The fungus has grown into the
hair follicle and will not be removed by topical treatment only. Severe
pustular forms exist with follicular pustules and nodules and often massive
purulent secretion. Lymph nodes in the neck swell and the patient
may have a fever and headache. There may be bacterial superinfection.
Systemic treatment is necessary to prevent scarring leading to permanent
bald patches.
Management of tinea capitis
- Griseofulvin 500 mg once daily for 8-12 weeks in adults.
- Griseofulvin 10-15 mg/kg once daily for 8-12 weeks in children.
- Add Whitfield’s ointment or miconazole twice daily topically for 4 weeks.
- Continue treatment after 12 weeks if the infection has not cleared completely.
- Alternative: Ketaconazole 200 mg twice daily or terbinafine 250 mg once daily or
itraconazole 200 mg (2 tabs) once daily for 4-8 weeks in adults.
- Ask for signs of infection in siblings or friends of affected children or in pets or
farm animals (bald patches, rash) and have these treated.
- In case of bacterial superinfection: antiseptics and / or antibiotics.

FUNGAL / YEAST INFECTIONS

Fungal infections may occur at any age. Children may easily infect each
other or get infected by animals / pets. The most common fungal infection
is "athlete’s foot" = infection of the interdigital spaces of the toes.
Skin, nails and / or hair may be infected. When a fungal infection is treated
incompletely or too short it will almost certainly recur. In
immunosuppressed patients fungal infections may be more widespread
and take longer to treat than normal. Always ask your patient to come for
review when his or her treatment is about to be completed, If you then
see any remaining sign of infection continue the treatment, as it is likely
to recur if you do not.
MYCIDS
A hyperergic reaction to the fungus may occur in the course of fungal
infections. These are usually itchy eruptions of small blisters at a site distant
from the fungal infection, often the hands and fingers (pompholyx). No fungi
are found within these "mycids". They disappear when the causative fungal
infection is treated. Sometimes the itching is so severe that treatment is
advisable: a strong steroid cream under wet dressings for a couple of days.