Fungal infections Flashcards
What is a mycid?
A mycid is a hyperergic reaction that develops from a remote localized infection with no detectable fungus in the lesions.
What is a dermatophytid?
A dermatophytid is a type of mycid caused by a dermatophyte infection elsewhere in the body.
What are the criteria for diagnosing a dermatophytid?
Criteria for a dermatophytid include:
Proven dermatophytosis elsewhere
No fungal elements in the lesions
Initial worsening under systemic antimycotics
Clearing after treating the dermatophytosis
What is the most common type of dermatophytid?
The most common dermatophytid is a symmetrical dyshidrotic mycid of the hands, often associated with inflammatory mycotic infections of the feet, especially by Trichophyton mentagrophytes.
What treatments are effective for dermatophytids?
Effective treatments include systemic antimycotic therapy, short-term oral glucocorticosteroids, and a topical combination of an antifungal and glucocorticosteroid.
What is the overtreatment phenomenon?
The overtreatment phenomenon is a flare-up reaction that can occur with the initiation of systemic antifungal therapy, which can be managed with topical and systemic treatments.
What is the first-line topical treatment for tinea corporis?
An imidazole cream or Whitfield’s ointment applied twice daily for a minimum of 4 weeks.
How long should treatment for tinea corporis continue after symptoms have cleared?
Treatment should continue for one week after symptoms have cleared.
What is the systemic treatment for multiple, widespread lesions of tinea corporis in adults?
Griseofulvin 500 mg once daily for 2 to 6 weeks.
What is the dosage of griseofulvin for children with tinea corporis?
Griseofulvin 10–15 mg/kg once daily for 2 to 6 weeks.
What alternative systemic treatments are available for tinea corporis in adults?
Ketoconazole 200 mg once or twice daily or itraconazole 200 mg (2 tabs) once daily for 2 to 4 weeks.
What can be added to the treatment regimen if there is severe itching with tinea corporis?
A mild steroid may be added to the treatment regimen.
What is the first-line oral treatment for tinea capitis in adults?
Griseofulvin 500 mg once daily for 8-12 weeks.
What is the recommended dosage of griseofulvin for children with tinea capitis?
Griseofulvin 10-15 mg/kg once daily for 8-12 weeks.
What topical treatments can be added for tinea capitis?
Whitfield’s ointment or miconazole applied twice daily for 4 weeks.
What should be done if tinea capitis does not clear after 12 weeks of treatment?
Continue treatment if the infection has not cleared completely after 12 weeks.
What are the alternative systemic treatments for tinea capitis in adults
Ketoconazole 200 mg twice daily, terbinafine 250 mg once daily, or itraconazole 200 mg once daily for 4-8 weeks.
What should be done to prevent the spread of tinea capitis?
Check for signs of infection in siblings, friends of affected children, pets, or farm animals (bald patches, rash) and treat them.
How should a bacterial superinfection associated with tinea capitis be treated?
Use antiseptics and/or antibiotics to treat bacterial superinfection.
What is the usual treatment for thickened toenails due to tinea unguium?
Usually, no treatment is required. Thickened toenails may be softened using Whitfield’s ointment or urea 10-40% ointment and then thinned with a stone or a file.
When is systemic treatment indicated for infected toenails in tinea unguium?
Systemic treatment is indicated when there is pain or when the patient is young.
What is the recommended systemic treatment for infected toenails in adults with tinea unguium?
Griseofulvin 500 mg once daily until the affected nails have grown out completely, which may take a year or longer.
What is the treatment duration for griseofulvin in fingernail infections?
Continue griseofulvin treatment until the affected nails have grown out completely, which may take 4-9 months.
What should be considered if there is no improvement in fingernail infection after 2-4 months of griseofulvin treatment?
There may be a mixed infection or resistance to griseofulvin, and a systemic azole like ketoconazole, itraconazole, or terbinafine should be considered.
What is the alternative treatment for tinea unguium if griseofulvin is ineffective?
Ketoconazole 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, or terbinafine 250 mg once daily for 6-16 weeks.
How should chronic paronychia be managed?
Keep the area dry, adapt work conditions if necessary, bathe in betadine or potassium permanganate solution, apply an imidazole cream or GV paint twice daily, and massage the nailfold with a mild steroid to decrease swelling.
What is the mechanism of action of Griseofulvin?
Griseofulvin works by inhibiting microtubule function in fungal cells, disrupting mitosis, and acting as a fungistatic agent. It is deposited in keratin-rich tissues (skin, hair, nails), making them resistant to fungal invasion. Griseofulvin is selective for dermatophytes, such as Trichophyton, Microsporum, and Epidermophyton species.
What is athlete’s foot?
Athlete’s foot is a condition characterized by itchy, often macerated whitish scaling lesions and inflammation of the skin in the interdigital spaces of the foot, most commonly between the 4th and 5th toe
What causes athlete’s foot?
Athlete’s foot can be caused by fungi or bacteria. It is often seen in people wearing rubber boots or rubber/plastic shoes.
What is the key management strategy for athlete’s foot?
Keep the space in-between the toes dry by drying thoroughly after washing, exposing to air, using betadine scrub, GV paint, wearing cotton socks, and avoiding tight or hot shoes.
How can one prevent re-infection of athlete’s foot?
Prevent re-infection by changing socks daily and keeping the feet dry.
What topical treatments are recommended for athlete’s foot?
Use an imidazole cream or Whitfield’s ointment twice daily until a week after symptoms have cleared, usually a minimum of 4 weeks.
What is pityriasis versicolor?
Pityriasis versicolor is a common, chronic, superficial fungal infection caused by the yeast Pityrosporum, usually resulting in cosmetic complaints.
What factors can make Pityrosporum pathogenic?
Factors include warmth and humidity, pregnancy, serious underlying disease, or genetic predisposition.
How does pityriasis versicolor typically present?
It presents as dandruff on the scalp, with the infection spreading to the neck and upper trunk.
What is a key step in managing pityriasis versicolor?
Scrubbing the skin with a brush to remove infected scales
What should be avoided when treating pityriasis versicolor?
Avoid using Vaseline, olive oil, or palm oil.
What topical treatments are recommended for pityriasis versicolor?
Use an imidazole cream twice daily on affected areas for 4 weeks, and consider selenium sulfide shampoo or ketoconazole 2% shampoo for widespread lesions or recurrences.
What oral treatments are recommended for severe recurrent cases of pityriasis versicolor?
Ketoconazole 400 mg stat, ketoconazole 200 mg once daily for 5 days, or itraconazole 200 mg once daily for 1 week.
How do you determine if the treatment of pityriasis versicolor is complete?
The treatment is complete when all the scales have disappeared. Test by stretching affected skin; if scales appear, the infection is still active.
How should large oozing lesions from candidiasis be treated?
Treat with potassium permanganate dressings or baths for 10 minutes twice daily, and keep the lesional skin dry.
What is recommended for treating mucosal or smaller wet lesions in candidiasis?
Paint the lesions with Gentian Violet solution once daily until healed.
How is oral candidiasis treated with nystatin?
Use nystatin oral suspension, 1 ml swirled around the mouth four times daily until two days after clinical cure.
What is the treatment for vaginal candidiasis?
Use nystatin pessaries nightly for 2 weeks.
What topical treatment is recommended for skin infections caused by candidiasis?
Use an imidazole cream twice daily.
How should oral thrush be treated with miconazole?
Use miconazole oral gel, 5 ml four times daily for 1 week.
What is the treatment for nappy rash caused by candidiasis?
Apply an imidazole cream and cover with zinc oxide cream or ointment.
What systemic antifungal treatments are recommended for severe cases like esophageal thrush?
Use ketoconazole 200 mg twice daily for 1-2 weeks, itraconazole 100 mg once daily for 2 weeks, or fluconazole 50-200 mg once daily for 1-2 weeks
What is the recommended treatment for smaller mycetoma lesions?
Smaller lesions that can be surgically removed without causing disability should be radically excised.
How should the origin of mycetoma be determined before starting drug therapy?
Determine whether the mycetoma is of fungal or bacterial origin through direct microscopy of pus containing grains and culture. Eumycetomas show hyphae, while actinomycetomas show small slender filaments.
What is the primary difference between eumycetoma and actinomycetoma?
Eumycetoma is caused by fungi, whereas actinomycetoma is caused by bacteria.
What is the success rate of antifungal treatment for eumycetoma?
Antifungal treatments like itraconazole, fluconazole, ketoconazole, miconazole, and griseofulvin have a success rate of less than 30% for eumycetoma.
hat medications are used to treat actinomycetoma?
Dapsone or cotrimoxazole combined with streptomycin are used to treat actinomycetoma. Streptomycin can be substituted by amikacin, and sulfonamides by rifampicin.
What is often the last resort for treating mycetoma when drug therapy fails?
Radical surgery or amputation is often the only option when drug therapy fails.
