This document summarizes several types of fungal infections of the skin, including their causes, symptoms, diagnosis, and treatment. Dermatophyte infections like tinea capitis, tinea pedis, and tinea corporis typically present as ring-shaped patches with scaling and are diagnosed by microscopic examination. Candidiasis can cause oral or genital thrush and candidal skin rashes. Pityriasis versicolor is a common fungal infection that causes discolored, scaly skin patches. Treatment involves topical or oral antifungal medications.

1. DERMATOLOGY
fungal infection of
skin
prepared by:
Khwlah AL-
Shothmi

2. Dermatophytoses
• Dermatophytes are fungi that require
keratin for growth. These fungi can
cause superficial infections of the
skin, hair, and nails. Dermatophytes
are spread by direct contact from
other people (anthropophilic
organisms), animals (zoophilic
organisms), and soil (geophilic
organisms).

3. • as well as indirectly from fomites.
• Dermatophyte infections can be
readily diagnosed based on the
history, physical examination, and
potassium hydroxide (KOH)
microscopy.
• Diagnosis occasionally requires
Wood's lamp examination and fungal
culture or histologic examination.
• Topical therapy is used for most
dermatophyte infections.

4. Tinea Capitis
• Tinea capitis, the most common
dermatophytosis in children, is an infection
of the scalp and hair shafts.
• Transmission is fostered by poor hygiene
and overcrowding, and can occur through
contaminated hats, brushes, pillowcases,
and other inanimate objects.
• After being shed, affected hairs can
harbor viable organisms for more than one
year.

5. • Tinea capitis is characterized by irregular
or well-demarcated alopecia and scaling.
• When swollen hairs fracture a few
millimeters from the scalp, “black dot”
alopecia is produced.
• Tinea scalp infection also may result in a
cell-mediated immune response termed a
“kerion,” which is a boggy, sterile,
inflammatory scalp mass.
• Cervical and occipital lymphadenopathy
may be prominent.

8. • From the site of inoculation, the fungus
grows down into the stratum corneum,
where it invades keratin.
• Dermatophytes are unique in that they
produce keratinase, which enables them
to use keratin as a nutrient source.
• Infected hairs become brittle, and after
three weeks, the clinical presentation of
broken hairs is evident.
• There are three types of infection:

9. • Ectothrix: Characterized by the growth of
fungal spores (arthroconidia) on the
exterior of the hair shaft.
• Infected hairs usually fluoresce
greenish-yellow under a Wood lamp.
Associated with Microsporum
canis, Microsporum
gypseum, Trichophyton equinum,
and Trichophyton verrucosum.

10. • Endothermic: Similar to ectothrix, but
characterized by arthroconidia restricted to
the hair shaft, and restricted to
anthropophilic bacteria.
• The cuticle of the hair remains intact and
clinically this type does not have
florescence.
• Associated with Trichophyton
tonsurans and Trichophyton violaceum,
which are anthropophilic.
• Favus: Causes crusting on the surface of
the skin, combined with hair loss.

12. Clinical Manifestation
• Noninflammatory Infection. Scaling.
Diffuse or circumscribed alopecia.
Occipital or posterior auricular
adenopathy.
• “Black Dot” Tinea Capitis. Broken-off hairs
near the scalp give appearance of “dots”
(swollen hair shafts) in dark-haired
patients.

13. Clinical Manifestation
• Kerion. Inflammatory mass in which
remaining hairs are loose.
Characterized by boggy, purulent,
inflamed nodules, and plaques.
Favus Latin for honeycomb, Early cases
show perifollicular erythema and matting
of hair.

14. Laboratory investigations
• Wood’s Lamp.
• Direct Microscopy.
• Fungal Culture.
• Bacterial Culture.

16. Tinea pedis
• Tinea pedis, or athlete's foot, has three
common presentations. The interdigital
form of tinea pedis is most common.
• It is characterized by fissuring,
maceration, and scaling in the interdigital
spaces of the fourth and fifth toes.
• Patients with this infection complain of
itching or burning.

17. • A second form, usually caused by
Trichophyton rubrum, has a moccasin-like
distribution pattern in which the plantar
skin becomes chronically scaly and
thickened, with hyperkeratosis and
erythema of the soles, heels, and sides of
the feet.
• The vesiculobullous form of tinea pedis is
characterized by the development of
vesicles, pustules, and sometimes bullae
in an inflammatory pattern, usually on the
soles.

19. Differential diagnosis
• contact dermatitis.
• eczema.
• pustular psoriasis.

20. Tinea manuum
• Tinea manuum is a fungal infection of one
or, occasionally, both hands.
• It often occurs in patients with tinea pedis.
The palmar surface is diffusely dry and
hyperkeratotic.
• When the fingernails are involved,
vesicles and scant scaling may be
present, and the condition resembles
dyshidrotic eczema.

21. Differential diagnosis
• contact dermatitis.
• psoriasis.
• callus formation.

23. Treatment
• Topical antifungal therapy and the
application of emollients containing lactic
acid (e.g., Lac-Hydrin Cream) are
effective.
• Relapses may be frequent if
onychomycosis or tinea pedis is not
resolved.

24. Tinea cruris
• Tinea cruris, frequently called “jock itch,” is
a dermatophyte infection of the groin.
• This dermatophytosis is more common in
men than in women and is frequently
associated with tinea pedis.
• Tinea cruris occurs when ambient
temperature and humidity are high.
• Occlusion from wet or tight-fitting clothing
provides an optimal environment for
infection.

25. • Tinea cruris affects the proximal medial
thighs and may extend to the buttocks and
abdomen. The scrotum tends to be
spared. Patients with this dermatophytosis
frequently complain of burning and
pruritus. Pustules and vesicles at the
active edge of the infected area, along
with maceration, are present on a
background of red, scaling lesions with
raised borders. The feet should be
evaluated as a source of the infection.

26. CONDITION DISTINGUISHING FEATURES
Candidal intertrigo Uniformly red, with no central clearing; satellite
lesions
Erythrasma Uniformly brown and scaly, with no active edge;
fluoresces a brilliant coral red
Mechanical intertrigo Sharp edge, no central clearing or scale
Psoriasis Silvery scale and sharp margination; pitted nails;
knee, elbow, and scalp lesions
Seborrheic dermatitis Greasy scales; scalp (dandruff) and sternal
involvement

28. Treatment
• Adjunctive treatment can include a low-
dose corticosteroid (e.g., 2.5 percent
hydrocortisone ointment [Cortaid]) for the
first few days. Rarely, systemic antifungal
therapy is needed for refractory tinea
cruris. Patient education on avoiding
prolonged exposure to moisture and
keeping the affected area dry is important.

29. Tinea facialis
• Tinea facialis tends to occur in the non-
bearded area of the face. The patient may
complain of itching and burning, which
become worse after sunlight exposure.
Some round or annular red patches are
present. Often, however, red areas may
be indistinct, especially on darkly
pigmented skin, and lesions may have
little or no scaling or raised edges.
Because of the subtle appearance, this
dermatophytosis is sometimes known as
“tinea incognito

31. Treatment
consists of measures to decrease
excessive skin moisture and the use of
topical antifungal creams.

32. Tinea corporis
• Tinea corporis, or ringworm, typically
appears as single or multiple, annular,
scaly lesions with central clearing, a
slightly elevated, reddened edge, and
sharp margination (abrupt transition from
abnormal to normal skin) on the trunk,
extremities, or face.
• The border of the lesion may contain
pustules or follicular papules. Itching is
variable.

33. • The diagnosis of tinea corporis is based
on clinical appearance and KOH
examination of skin scrapings from the
active edge.
• Previous topical corticosteroid use can
alter the appearance of the lesions, so
that raised edges with central clearing are
not present. Corticosteroid use may also
be a factor in the development of
Majocchi's granuloma, a deep follicular
tinea infection that usually involves the
legs and is more common in women.

35. Majocchi's granuloma

36. Treatment
• Treatment of tinea corporis usually
consists of measures to decrease
excessive skin moisture and the use of
topical antifungal creams.
• Rarely, widespread infections may require
systemic therapy.

37. Tinea unguium
• Tinea unguium, a dermatophyte
infection of the nail, is a subset of
onychomycosis, which also may be
caused by yeast and non-dermatophyte
molds.
• Risk factors for this infection include
aging, diabetes, poorly fitting shoes,
and the presence of tinea pedis.

38. • Onychomycosis accounts for about 40
to 50 percent of nail dystrophies.
• The differential diagnosis includes
trauma, lichen planus, psoriasis, nail-
bed tumor, peripheral vascular disease,
atopic dermatitis, contact dermatitis,
and yellow nail syndrome.

39. • Periodic acid-Schiff staining with
histologic examination of the clipped,
distal free edge of the nail and
attached subungual debris is the most
sensitive diagnostic method and is
painless for patients.

41. • Tinea unguium, especially of the toenails,
is difficult to eradicate. Topical agents
have low efficacy. Mycologic cure rates for
ciclopirox (Penlac) nail lacquer, applied
daily for up to 48 weeks, have ranged from
29 to 47 percent. Oral treatment with
griseofulvin must be continued for 12 to
24 months, and ketoconazole carries a
risk of hepatotoxicity. Fluconazole has
not been studied extensively in the
treatment of onychomycosis and is not
labeled by the FDA for this indication.

42. Tinea barbae
• Tinea barbae involves the skin and coarse
hairs of the beard and mustache area.
This dermatophyte infection occurs in
adult men and hirsute women. Because
the usual cause is a zoophilic organism,
farm workers are most often affected.
Tinea barbae may cause scaling, follicular
pustules, and erythema

44. Treatment
• Like tinea capitis, tinea barbae is treated
with oral antifungal therapy. Treatment is
continued for two to three weeks after
resolution of the skin lesions.

45. Candidiasis
• Candidiasis is a fungal infection due to
any type of Candida (a type of yeast).
When it affects the mouth, it is commonly
called thrush.
• Signs and symptoms include white
patches on the tongue or other areas of
the mouth and throat.Other symptoms
may include soreness and problems
swallowing.

46. • When it affects the vagina, it is commonly
called a yeast infection.
• Signs and symptoms include genital
itching, burning, and sometimes a white
"cottage cheese-like" discharge from the
vagina.
• Yeast infections of the penis are less
common and typically present with an
itchy rash.

47. • Very rarely, yeast infections may become
invasive, spreading to other parts of the
body.
• This may result in fevers along with other
symptoms depending on the parts
involved.

51. What are the symptoms of candidiasis
of the skin?

52. • The main symptom of candidiasis of the
skin is a rash. The rash often causes
redness and intense itching.
• In some cases, the infection can cause
the skin to become cracked and sore.
Blisters and pustules may also occur.

53. • The rash can affect various parts the
body, but it’s most likely to develop in
the folds of the skin.
• This includes areas in the armpits, in
the groin, between the fingers, and
under the breasts.
• Candida can also cause infections in the
nails, edges of the nails, and corners of
the mouth.

54. Who are at risk?
• warm weather
• tight clothing
• poor hygiene
• infrequent undergarment changes
• obesity
• the use of antibiotics that kill harmless
bacteria that keep Candida under control

55. • the use of corticosteroids or other
medications that affect the immune
system
• a weakened immune system as a
result of diabetes, pregnancy, or
another medical condition
• incomplete drying of damp or wet skin.

56. How is candidiasis of the skin
diagnosed?
• physical examination.
• perform a skin culture

57. Treatment
• Candidiasis of the skin can usually be
prevented with home remedies, the most
important of which is proper hygiene.
Washing the skin regularly and drying the
skin thoroughly can prevent the skin from
becoming too moist. This is vital to
keeping Candida infections at bay.
• There are many lifestyle changes you can
make to both prevent and treat a
candidiasis infection.

58. Pityriasis versicolor
• Pityriasis versicolor, sometimes called
tinea versicolor, is a common fungal
infection that causes small patches of skin
to become scaly and discoloured.
• The patches may be darker or lighter than
your normal skin colour, or may be red,
brown or pink. They tend to develop
gradually and may join up to form larger
patches over time.

60. Why it happens?
• Pityriasis versicolor is caused by a type
of yeast called Malassezia. This yeast is
found on the skin of more than 90% of
adults, where it normally lives without
causing any problems.
• But pityriasis versicolor can develop if
this yeast starts to multiply more than
usual. It's not clear exactly why this
happens in some people and not in
others.

61. Risk factors
• living or staying in a warm, moist
environment, including the UK, in the
summer
• sweating excessively (hyperhidrosis)
• creams, dressings or clothing that don't
allow skin to breathe.
• being malnourished.
• having a weakened immune system.
• being a teenager or in early 20s.

62. Treatment
• Antifungal shampoos (such as
ketoconazole or selenium sulphide
shampoo) are often the first treatment
recommended for pityriasis versicolor.