The lecture has been given on Apr. 17th, 2011 by Dr. Darseem.

1. Fungal infections of the skin Dermatophytosis Candidiasis Pityriasis versicolor Deep fungal infections

2. Derotophyte infections (ringworm) Cause Three generate of dermatophyte fungi cause tinea infections (ringworm): 1. Ttichophyton-skin, hair and nail infections. 2. Microsporum-skin and hair. 3. Epidermophyton-skin and nail.

3. Dermatophytes invade the keratin only, and the inflammation they cause is due to: -metabolic products of the fungus or -delayed hypersensitivity. In general, zoophilic fungi (those transmitted to humans by animals) cause a more severe inflammation than anthropophilic ones (spread from person to person).

4. Presentation and course: Depends upon the site and strain of fungus involved. Tenia pedis (athlete's foot) Most common type of fungal infection in humans. The sharing of wash places (e.g. in showers) and of swimming pools, predisposes to infection. Occlusive footwear encourages relapse. Most cases are caused by one of three organisms: Trichophyton rubrum (the most common and the most stubborn), Trichphyton mentagrophytes var. intrdigitale and Epidermophyton floccosum.

5. There are three common clinical patterns: 1. Soggy interdigital scaling, particularlyin the fourth and fifth interspace (all three organisms). 2. Diffuse dry scaling of the sole (uaually T. rubrum ). 3. Recurrent episodes of vesication ( usually T. mentagrophytes var. interdigitale or E. floccosum ).

9. Tenia of the nails (onychomycosis): -Toenail infection usually associated with tinea pedis. -The initial changes occur at the free edges of the nails, which becomes yellow and crumbly. -Subangual hyperkeratosis, separation of the nail from its bed, and thickening may then follow. -Usually only a few nails are infected but rarely all are. -Fingernail lesions are similar, but less common, and are seldom seen without a chronic T. rubrum infection of the skin of the hands.

11. Tinea of the hands (tinea manum): This is usually asymmetrical and associated with tinea pedis. T. rubrum may cause a barely perceptible erythema of one palm with a characteristic powdery scale in the creases.

13. Tinea of the groin (tinea cruris): -This is common and affects men more than women. -The eruption is sometimes unilateral or asymmetrical. -The upper inner thigh is involved and lesions expand slowly to form sharply demarcated plaques with peripheral scaling. -In contrast to candidiasis of the groin area, the scrotum is usually spared. -A few vesicles or pustules may be seen within the lesions. -The organisms are the same as those causing tinea pedis.

15. Tinea of the trunk and limbs (tinea corporis): -Characterized by plaques with scaling and erythema most pronounced at the periphery. -Few small vesicles and pustules may be seen within them. The lesions expand slowly, healing in the centre and leaves a typical ring-like pattern.

17. Tinea of the scalp (tinea capitis) This is usually a disease of children. The causative organism varies from country to country. Fungi coming from animal sources (zoophilic fungi) induce a more intense inflammation than those spread from person to person (anthropophilic fungi).

18. Types: 1. In ringworm acquired from cattle, for example, the boggy swelling, with inflammation, postulation and lymphadenopathy, is often so fierce that a bacterial infection is suspected; such a lesion is called a kerion and the hair loss associated with it may be permanent. Tenia of the beard area is usually caused by zoophilic species and shows the same features.

19. 2. Anthropophilic organisms cause bald rather scaly areas with minimal inflammation and hairs broken off 3-4 mm from the scalp. 3. In favus, caused by T. schoenleini , crusts surrounding many scalp hairs, and sometimes leading to scarring alopecia.

22. Complications: 1. Fierce ringworm of the scalp can lead to a permanent scarring alopecia. 2. Fungal infection anywhere can induce vesication on the sides of fingers and palms. 3. Epidemics of ringworm occur in schools. 4. The usual appearance of a fungal infection can be masked by mistreatment with topical steroids (tinea incognito).

23. Investigations: 1. Microscopic examination of skin scrapping, nail clipping or a plugged hair. The scrapping should be taken from the scaly margin of a lesion with a small curette or a scalpel glade, and clippings/scrapings from the most crumbly part of a nail. Broken hairs should be plucked with tweezers. Specimens are cleared in potassium hydroxide. Branching hyphae can easily be seen using a scanning(x10) or low-power (x25) objective lens. Hyphae may also be seen within a cleared hair shaft, or spores may be noted around it.

24. 2. Cultures may be carried out in a mycology or bacteriology laboratory. Transport medium is not necessary, and specimens should be sent in folded black paper. The report may take as long as a month; microscopy is much quicker.

25. 3. Wood's light (ultraviolet light) examination of the scalp usually reveals a green fluorescence of the hairs in Microsporum audouini and Microsporum canis infections. The technique is useful for screening children in institutions where outbreaks of tinea capitis still sometimes occur, but some fungi (e.g. Trichophyton tonsurans ) do not fluoresce.

26. Treatment: Local: This is all that is needed for minor skin infections. The more recent imidazole preparations (e.g. miconazole and clotrimazole) and the allylamines such as terbinafine should be applied twice daily. Magenta paint (Castellani's paint) although highly colored, is useful for exudative or macerated areas in body folds or toe webs. Occasional dusting with an antifungal powder is useful to prevent relapses.

27. Topical nail preparations: Many patients prefer to avoid systemic treatment. For them a nail lacquer containing amorolfine is worth a trial. It should be applied once or twice a week for 6 months. It is effective against stubborn moulds such as Hendersonula and Scopulariopsis . Both amorolfine and tioconazole nail solutions can be used as adjuncts to systemic therapy.

28. Systemic; This is needed for tinea of the scalp or of the nails, and for widespread or chronic infections of the skin that have not responded to local measures.

29. Terbinafine: It acts by inhibiting fungal squaline epoxidase and does not interact with the cytochromeP-450 system. It is fungicidal and so cures chronic dermatophyte infections more quickly and more reliably than griseofulvin. For tinea capitis in children, for example, a 4 weeks course of terbinafine is effective as an 8 weeks course of griseofulvin. Cure rates of 70-90% can be expected for infected finger nails after a 6weeks course of terbinafine, and for infected toe nails after a 3 months course. It is not effective for pityriasis versicolor or Candida infections.

30. Griseofulvin: was for many years the drug of choice for chronic dermatophyte infections. It has proved to be safe drug, but treatment may have to be stopped because of persistent headache, nausea, vomiting or skin eruption. The drug should not be given in pregnancy or to patients with liver failure or porphyria. It interacts with coumarin anticoagulants, the dose of which may have to be increased. Its effectiveness falls if barbiturars are been taken at the same time.

31. Griseofulvin is bacteriostatic and treatment for infected nails has to be prolonged (an average of 12 months for finger nails, and at least 18 months for toe nails). The disappointing results for toe nail infections seen in some 30-40% of cases can be improved by the concomitant use of topical nail preparations.

32. Itraconazole: is now preferred to ketoconazole, which occasionally damagesthe liver, and is reasonable alternative to terbinafine and griseofulvin if these are contraindicated. It is effective in tinea corporis, cruris and pedis; and also in nail infections. Fungistatic rather than fungicidal, it interferes with cyochrome P-450 system, so the review of any other medication being taken is needed before a prescription is issued. Its wide spectrum makes it useful also in pityriasis versicolor and candidiasis.

33. Candidiasis: Cause: Candida albicans is a classic opportunistic pathogen. Even in transient and local infections in the apparently fit, one or more predisposing factors such as obesity, moisture and maceration, diabetes, pregnancy, the use of broad-specrtum antibiotics, or perhaps the use of the oral contraceptive pill, will often be found to be playing some part. Opportunism is often more obvious in the overwhelming systemic infections of the immunocompromized.

34. Presentation Oral candidiasis; -One or more whitish adherent plaques appear on the mucous membranes. -If wiped off they leave an erythematous base. -Under dentures, candidiasis will produce sore red areas. -Angular stomatitis, usually in denture wears may be candidiasis.

37. Candida intertrigo; -A moist glazed area of erythema and maceration appears in a body fold; the edge shows soggy scaling, and outlying satellite papulopustules. -These changes are most common under the breasts, and under the armpits and groin, but can also occur between the fingers of those whose hands are often in water.

41. Genital candidiasis: -Present as a sore itchy vaginitis with white curdy plaques adherent to the inflamed mucous membranes, and a whitish discharge. -The eruption may extend to the groin folds. -Conjugal spread is common; in males similar changes occur under the foreskin and in the groin. -Diabetes, pregnancy and antibiotic therapy are common predisposing factors.

42. Paronychia: -Acute paronychia is usually bacterial, but in chronic paronychia candida may be the sole pathogen, or be found with other opportunists such as proteus or pseudomonas.

43. -Proximal and sometimes the lateral nail folds of one or more fingers becomes bolstered and red. -The cuticles are lost and small amounts of pus can be expressed. -The adjacent nail plate becomes ridged and discolored. -Predisposing factors include wet work, poor peripheral circulation and vulval candidiasis.

45. Chronic mucocutaneous candidiasis: -persistent candidiasis, affecting most or all of the areas described above, can start in infancy. -Sometimes the nail and the nail folds are involved. -Candida granulomas may appear on the scalp. -Several different forms have been described including those with autosomal recessive and dominant inherited patterns.

46. -In the candida endocrinopathy syndrome, chronic candidiasis occurs with one or more endocrine defect, the most common of which are hypoparathyroidism, and addison's disease. -A few late onset cases have underlying thymic tumours.

47. Systemic candidiasis: -This is seen against a background of severe illness, leukemia and immunosupression. -The skin lesions are firm red nodules, which can be shown by biopsy to contain yeasts and pseudohyphae.

48. Investigations: -Swabs from suspected areas should be sent for cultures. -The urine should always be tested for sugar. -In chronic mucocutaneous candidiasis, a detailed immunological work-up will be needed, focusing on cell mediated immunity.

49. Treatment: -Predisposing factors should be sought and eliminated; e.g. dental hygiene may be important. -Infected skin folds should be separated and kept dry. -Those with chronic paronychia should keep their hands worm and dry.

50. -Amphotericin, nystatin, and the imidazole group of compounds are all effective topically, for the mouth, these are available as oral suspensions, lozenges and oral gels. -False teeth should be removed at night, washed and steeped in a nystatin solution.

51. -For other areas of candidiasis, creams, ointments and pessaries are available. -Magenta paint is also useful but messy for the skin flexures. -In chronic paronychia, the nail folds can be packed with an imidazole cream or drenched in an imidazole solution several times a day.

52. -Genital candidiasis responds well to a single day's treatment with either itraconazole and fluconazole. Both are also available for recurrent oral candidiasis of the immunocompromized, and for the various types of chronic mucocutaneous candidiasis.

53. Pityriasis versicolor: Cause; -Commensal yeasts ( pityrosporum orbiculre ), overgrowth of these, particularly in hot humid conditions, is responsible of the clinical lesions. -Carboxylic acids released by the organisms inhibit the increase in pigment production by melanocytes that occurs normally after exposure to sunlight. -The term versicolor refers to the way in which the superficial scaly patches, fawn or pink on non-tanned skin, become paler than the surrounding skin after exposure to sunlight. -The condition should be regarded as non-infectious.

54. Presentation and course: -The fawn or depigmented areas, with their slightly branny scaling and fine wrinkling, look ugly. -Otherwise they are symptom-free or only slightly itchy. -Lesions are most common on the upper trunk but can become widespread. -Untreated lesions persist, and depigmented areas, even after adequate treatment, are slaw to regain their former color. -Recurrences are common.

56. Differential diagnosis: -In vitiligo , the border is clearly defined, scaling is absent, lesions are larger, the limbs and face are often affected , and depigmentation is more complete; however, it may sometimes be hard to distinguish vitiligo from the pale non-scaly areas of treated versicolor. -Seborrhoeic eczema of the trunk tends to be more erythematous, and is often confined to the presternal or interscapular areas. -Pityriasis alba often affects the cheeks. -Pityriasis rosea, tinea corporis, secondary syphilis and erythrasma seldom cause real confusion.

57. Investigations: -Scrapings, prepared and examined as for the dermatophyte infection, show a mixture of short branched hyphae and spores ( a spaghetti and meat-balls' appearance). -Culture is not helpful.

58. Treatment: -a topical preparation of one of the imidazole group of anti-fungal drugs can be applied at night to all affected areas for 2-4 weeks. -Equally effective, but messier and more irritant, is a 2.5% selenium sulphide mixture in a detergent base (selsun shampoo). This should be lathered on to the patches after an evening bath, and allowed to dry. Next morning it should be washed off. Three applications at weekly intervals are adequate.

59. -A shampoo containing ketoconazole is now available and is less messy, but just as effective as the selenium ones. -For wide spread or stubborn infections systemic itraconazole (200mg daily for 7 days) has been shown to be curative, but interactions with other drugs must be avoided. -Recurrence is common after any treatment.

60. Deep fungal infections: Histoplasmosis: - Histoplasma capsulatum is found in soil and in the droppings' of some animals (bat). -Airborn spores are inhaled and cause lung lesions, which are in many ways like those of tuberculosis. -Later, granulomatous skin lesions may appear, particularly in the immunocompromised. -Amphotericin B or itraconazole given systemically, is often helpful.

61. Coccidioidomycosis: -The causative organism, Coccidioides immitis , is present in the soil in arid areas in the USA. -Its spores are inhaled, and the pulmonary infection may be accompanied by a fever. -At this stage erythema nodosum may be seen. -In a few patients the infection becomes disseminated, with ulcers or deep abscesses in the skin. -Treatment is with amphotericin B or itraconazole.

63. Blastomycosis: -Infections with Blastomyces dermatitidis are virtually confined to rural areas of the USA. -Rarely, the organism is enoculated into the skin; more often it is inhaled and then spreads systemically from the pulmonary focus to other organs including the skin. -There the lesions are wart-like, hyperkeratotic nodules, which spread peripherally with a verrucose edge, while tending to clear and scar centrally. -Treatment is with amphotericin B or itraconazole.

65. Sporotrichosis: -The causative fungus Sporotrichum schencki , lives supprophytically in soil or on wood in warm humid countries. -Infection is through a wound, where later a lesion like an indolent boil arises. -Later still, nodules appear in succession along the draining lymphatics. -KI or itraconazole are both effective.

67. Actinomycosis: -The causative organism, Actinomyces Israeli , is bacrerial but traditionally considered with a fungi. -It has long branching hyphae and is part of the normal flora of the mouth and bowel. -In actinomycosis, a lumpy induration and scarring coexist with multiple sinuses discharging puss containing sulphur granules, made up of tangled filaments. -Favourite sites are the jaw, and the chest and abdominal walls. -Long-term penicillin is the treatment of choice.

69. Mycetoma (Madura foot): -Various species of fungus or actinomycetes may be involved. -They gain access to the subcutaneous tissues, usually of the feet or legs, via a penetrating wound. -The area becomes lumpy and distorted, later enlarging and developing multiple sinuses. -Puss exuding from these shows tiny diagnostic granules. -Surgery may be a valuable alternative to the often poor results of medical treatment, which is with systemic antibiotics or anti-fungal drugs, depending on the organism isolated.