1. Chapter 16
Fungal infections

2. Fungal infections Dermatophyte infections (ringworm)
3 genera cause tinea:
Trichophyton – skin, hair & nail infections.
Microsporum – skin and hair.
Epidermophyton – skin and nails.
Invade only into the stratum corneum
Inflammation result of
Metabolic products
Delayed hypersensitivity.
Zoophilic fungi
From animals to humans
cause a more severe inflammation
Anthropophilic ones
Spread from person to person
Yeasts:
Candidiasis
Pityriasis virsicolor

3. Active border, which contains vesicles that indicate acute inflammation.
Active border (classic presentation).
Red, scaly, and slightly raised.
The central area is often lighter than the surrounding normal skin.

4. Tinea pedis (athlete’s foot)
Most common
Predispose to infection:
Sharing of wash places (e.g. in showers)
Swimming pools
Most cases are caused by
Trichophyton rubrum (most common & stubborn)
Trichophyton mentagrophytes
Epidermophyton floccosum
3 common clinical patterns.
Soggy interdigital scaling (particularly in the 4th & 5th interspace.
A diffuse dry scaling of the soles (usually T. rubrum).
Recurrent episodes of vesication (usually T. mentagrophytes var. interdigitale or E. floccosum).

5. Fig. 16.38 Tinea pedis. Scaly area spreading to the sole from the toe webs.
Soggy interdigital scaling
Fig Powdery scaling, most obvious in the skin creases, caused by a Trichophyton rubrum infection.
A diffuse dry scaling of the soles

6. The toe web space contains macerated scale
The toe web space contains macerated scale. The fourth web is the most commonly involved web space.
The infection has spread out of the toe web.
A chronic toe web and dorsal foot fungal infection have become secondarily infected with staphylococci.

7. Tinea of the nails Usually associated with tinea pedis.
Changes: (DLSO)
The free edge of the nail becomes yellow & crumbly
Subungual hyperkeratosis
Onycholysis: separation of the nail from its bed
Thickening
Splinter hemorrhage
Fig Chronic tinea of the big toe nail. Starting distally, the thickness and discoloration are spreading proximally.

8. Distal subungual onychomycosis
White superficial onychomycosis
Proximal subungual onychomycosis

9. Four types of onychomycosis showing different entry points by infecting organisms.

10. Tinea of the hands Asymmetrical Associated with tinea pedis
Unilateral onychomycosis.
Trichophyton rubrum may cause
A barely perceptible erythema of one palm
With a characteristic powdery scale in the creases.

11. The infected areas are red with little or no scale
The infected areas are red with little or no scale. Note infection of the fingernails
Prominent scaling border
Wel-defined red border

12. Diffuse erythema and scaling
The involved palm is thickened, very dry, and scaly.

13. Tinea of the groin Common Affects men more often than women.
The eruption is sometimes unilateral or asymmetrical.
The upper inner thigh is involved
Lesions expand slowly to form sharply demarcated plaques with peripheral scaling.
Scrotum is usually spared (in contrast to candidiasis)
A few vesicles or pustules may be seen
The organisms are the same as those causing tinea pedis.
Fig A very gross example of tinea of the groin. The Trichophyton rubrum infection has spread on to the abdomen and thighs, aided by the use of topical steroids.

14. Candida groin infection. Tinea of the groin
More extensive & Bilateral.
Infect the scrotum
Typical fringe of scale at the border
Satellite pustules
Tinea of the groin
Half-moon–shaped plaque
Well-defined & scaling border.

15. Tinea corporis Tinea of the trunk & limbs
Plaques
Scaling
Erythema most pronounced at the periphery
A few small vesicles and pustules may be seen within them.
The lesions expand slowly
Healing in the centre leaves a typical ring-like pattern.
In some patients the fungus elicits almost no inflammation, in which case the infection is a marginated patch of rough scaling skin.
Red, scaly border

16. Tinea capitis Tinea of the scalp
Kerion: in ringworm acquired from cattle, boggy swelling with
Inflammation
Pustulation
Lymphadenopathy
Bacterial infection is suspected
Hair loss may be permanent.
Tinea of the beard area is usually caused by zoophilic species and shows the same features.
Favus caused by Trichophyton schoenleini
Foul-smelling yellowish crusts surrounding many scalp hairs, and sometimes leading to scarring alopecia.
Black children are especially prone to infection with Trichophyton tonsurans.
Usually a disease of children.
The causative organism varies from country to country.
Anthropophilic organisms cause bald and scaly areas, with minimal inflammation and hairs broken off 3–4 mm from the scalp.
Zoophilic fungi induce a more intense inflammation.

17. Fig. 16.42 Animal ringworm of the beard area showing boggy inflamed swellings (kerion).
Fig Animal ringworm of a child’s scalp: not truly a kerion as flat and non-pustular.

18. Kerions
Deep, boggy, papular and pustular red lesions
Cervical lymphadenopathy may develop
Severely inflamed deep lesion has accumulated serum and crust on the surface.
Cervical lymphadenopathy was present
Scarring alopecia

19. 4 distinct clinical patterns of tinea capitis caused by Trichophyton tonsurans
Noninflammatory “black dot” scaling pattern. Infection of the hair causes the shaft to fracture, leaving infected hair stubs. The color of the hair determines the color of the dots. Black hair presents with black dots. Light hair presents with white dots.
Kerions
Inflammatory tinea capitis

20. Seborrheic dermatitis type most difficult to diagnosis because it resembles dandruff
Pustular type
Pustules or scabbed areas without
Scaling or significant hair loss

21. Favus caused by Trichophyton schoenleini
Foul-smelling yellowish crusts
May leading to scarring alopecia

22. Complications Permanent scarring alopecia (Fierce animal ringworm).
Trichophytid (id reaction): A florid fungal infection induce vesication on the sides of the fingers and palms.
Epidemics of ringworm occur in schools.
Tinea incognito: the usual appearance of a fungal infection can be masked by mistreatment with topical steroids.
Fig ‘Tinea incognito’. Topical steroid applications have thinned the skin and altered much of the morphology. A recognizable active spreading edge is still visible.

23. Id reaction Tinea incognito.
Characteristic features of tinea are missing.

25. Investigations Microscopic examination of a Skin scraping
Nail clipping
Plucked hair
Cultures
Wood’s light
Green fluorescence in Microsporum audouini and M. canis infections.
Useful for screening
Trichophyton tonsurans does not fluoresce.

26. Treatment (local or systemic)
Imidazo (miconazole)
Allylamines (terbinafine)
Benzoic acid ointment (Whitfield’s ointment)
Tolnaftate
Magenta paint (Castellani’s paint)
Topical nail preparations
lacquer
containing amorolfine
Ciclopirox

27. Systemic needed for
Tinea of the scalp & nails
Widespread or chronic infections
Terbinafine
Fungicidal
Not interact with the cytochrome P-450 system
Not effective in pityriasis versicolor or Candida infections.
Itraconazole
Fungistatic
Interferes with cytochrome P-450 system
Useful also in pityriasis versicolor and candidiasis
Griseofulvin
May cause persistent headache, nausea, vomiting or skin eruptions.
Not be given in
Pregnancy
Patients with liver failure or porphyria
Interacts with coumarin anticoagulants (inc. the dosage)

28. Candidiasis Cause: Candida albicans Opportunistic pathogen
Predisposing factors:
Obesity
Moisture
Maceration
Immobility DM
Pregnancy
Broad-spectrum antibiotics
Contraceptive pill

29. Fig
Sites susceptible to Candida infection.

30. 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 wearers may be candidal.
Fig Candidal angular stomatitis associated with severe candidiasis of the tongue.
The hard palate is red and swollen

31. Candida intertrigo
A moist glazed area of erythema and maceration appears in a body fold
The edge shows soggy scaling
Outlying satellite papulopustules
Most common under the
Breasts
Armpits
Groin
Can also occur between the fingers of those whose hands are often in water.
Numerous satellite pustules beyond the intertriginous area
Candidiasis of the axillae

32. Genital candidiasis Most commonly presents as
Sore itchy vulvovaginitis
White curdy plaques adherent to the inflamed mm.
Whitish discharge.
The eruption may extend to the groin folds.
Conjugal spread is common
In males, similar changes occur under the foreskin & groin.
Predisposing factors( DM, pregnancy & antibiotic)
Fig Pink circinate areas with only a little scaling.
Consider Reiter’s syndrome or candidiasis.

33. Multiple red, round erosions are present on the glans and shaft of the penis.
There is a white exudate
thick white exudate is typical of a severe acute infection.

34. Paronychia Acute paronychia is usually bacterial
Chronic paronychia Candida may be the sole pathogen, or Proteus or Pseudomonas sp.
The proximal and sometimes the lateral nail folds of one or more fingers become bolstered.
The cuticles are lost and small amounts of pus can be expressed.
The adjacent nail plate becomes ridged & discoloured.
Predisposing factors:
Wet work
Poor peripheral circulation
Vulval candidiasis

35. Acute paronychia
Chronic paronychia

36. Chronic mucocutaneous candidiasis
Persistent candidiasis
Can start in infancy.
Affecting most of the areas
Sometimes the nail plates as well as the nail folds are involved.
Candida granulomas may appear on the scalp (several different forms including those with AR Ad inheritance patterns).
Candida endocrinopathy syndrome,
Chronic candidiasis
With one or more endocrine defects:
Hypoparathyroidism
Addison’s disease.
A few late-onset cases have underlying thymic tumours.

37. Systemic candidiasis Severe illness: Leucopenia Immunosuppression.
The skin lesions are firm red nodules, which can be shown by biopsy to contain yeasts and pseudohyphae.

38. Investigations:
Swabs & culture.
The urine can be tested for sugar.
Detailed immunological work-up (CMC)
Treatment
Eliminate predisposing factors
Topical antifungal: Amphotericin, nystatin and the imidazole group
Magenta paint
Imidazole cream or solution (chronic paronychia)
Itraconazole or fluconazole for
Genital candidiasis
Recurrent oral candidiasis of the immunocompromised
Chronic mucocutaneous candidiasis

39. Pityriasis versicolor
Non-infectious
Cause: commensal yeasts, Pityrosporum orbiculare
Overgrowth in hot humid conditions.
Release carboxylic acids, inhibit the increase in pigment production by melanocytes after exposure to sunlight.
Superficial Fawn or pink scaly patches on non-tanned skin
Become paler than the surrounding skin after exposure to sunlight
Fig Pityriasis versicolor: fawn areas stand out against the untanned background.

40. Presentation and course
Fawn or depigmented areas
Slightly branny scaling
Fine wrinkling
Ugly
Symptom-free or only slightly itchy.
Most common on
Upper trunk
Can become widespread.
Untreated lesions persist, and depigmented areas – even after adequate treatment – are slow to regain their former colour.
Recurrences are common.

41. Investigations: Scrapings DDx: Vitiligo
Depigmentation is more complete
The border is clearly defined
Scaling is absent
Lesions are larger
The limbs and face are often affected
Seborrhoeic eczema
More erythematous
Confined to the presternal or interscapular areas.
Pityriasis alba often affects the cheeks.
Pityriasis rosea, tinea corporis, secondary syphilis, leprosy and erythrasma seldom cause real confusion.
The central area was scraped to demonstrate white, powdery scale.

42. Treatment Topical Imidazole group
2.5% selenium sulphide mixture in a detergent base (Selsun shampoo).
Systemic
Itraconazole (200 mg/day for 7 days)
Fluconazole
Ketoconazole
Recurrence is common after any treatment.

43. White, oval, or circular patches on tan skin
Numerous circular, scaly lesions
fawn colored in untanned skin