Fungal Infections
Fungal infections are occasionally associated with a defect in host resistance which should, if possible, be corrected otherwise drug therapy may fail. Similarly, treatment of dermatophyte infection may be unsuccessful until the animal source has been removed or controlled.
If you suspect tinea please send generous scrapings of the skin or clippings of the nail to the Laboratory for direct examination and culture and please send these specimens before you start treatment with systemic anti-fungals.
NOTES: -
1. Think of tinea in any scaly rash that is not obviously psoriasis or eczema etc.
2. Asymmetrical scaly rashes should alert you to the possibility of tinea.
3. Nail dystrophy. Do undress the patients and look carefully for psoriasis.
4. Remember that candida does not respond to Griseofulvin or systemic Terbinafine (Lamisil).
5. Scalp ringworm and kerion only respond to oral antifungals, courses of which may be prolonged (8 weeks).
The topical products for nail fungal infection (Trosyl and Loceryl lacquer) are of limited benefit when used alone but cure rates may be improved when used in combination with systemic drugs.
Terbinafine (Lamisil)
The drug of choice for widespread dermatophyte infection of the skin and nails. It is not effective against yeasts such as candida. For fingernails a two to three month course, for toenails a four to six month course is required. The benefit continues after stopping the drug and you don’t need to continue until the nails are clinically and mycologically cured (as is the case with the less effective drug Griseofulvin). Cure rates are reported to be 70-80% (LION study) but relapses are common.
Please note: Lamisil is contra-indicated in anyone with hepatic and/or renal impairment.
Itraconazole (Sporanox)
This has the advantage of treating yeasts and moulds (such as candida) as well as dermatophytes. It is often prescribed for nails in the Sporanox Pulse form, giving it for one week out of four. Fingernails, two pulses and toenails, three pulses required.
Pityriasis Versicolor
Use Nizoral Shampoo, or Cream if localised, or alternatively Selsun Shampoo. If very widespread give Itraconazole (Sporanox) orally 200 mg per day for seven days. Lamisil is ineffective for Pityriasis Versicolor.