Fungal skin disease
1. Definition:
Fungal dermatosis can
also be called dermatophytosis. It refers to a large class of infectious
diseases of human skin, mucous membranes and skin appendages caused by medical
fungi. It is a common and frequent disease in dermatology.
Second
they have
real nuclei, produce spores, absorb nutrients in parasitic or saprophytic ways,
only a few groups are single cells, and there are branched or unbranched
filaments, which can perform sexual reproduction and (or) asexuality Organisms
that reproduce cell walls with chitinous microfibers or cellulose or both.
3rd
Nearly
200,000 kinds of fungi are found, of which only a few fungi are quite toxic and
can invade the human body. Most fungi are usually harmless, and they are only
invasive when the host's immunity is impaired, even threatening the patient's
life.
fungi can
be divided into two categories according to their morphology, namely yeast and
filamentous fungi, the latter is divided into dermatophytes and
non-dermatophyte fungi.
Fourth, the
classification of mycosis:
There are
five manifestations: invasive infection, opportunistic infection, fungal
allergy, fungal poisoning and fungal carcinogenesis
According
to the infection site, it can be divided into three categories: superficial
mycosis, subcutaneous tissue mycosis and systemic mycosis.
1. Superficial mycosis
refers to fungal
infections limited to the epidermis, skin appendages and mucous membranes. The
main pathogenic microorganisms are dermatophytes and Candida, most of which are
mild, easy to diagnose, and have good efficacy;
Deep
fungal disease: refers to those involving the dermis and below, internal
organs, blood and systemic fungi
1. Infection, the main pathogenic
microorganisms are Candida, Aspergillus Cryptococcus and Mucor, etc. Most of
them are opportunistic infections. Most patients have more serious basic
diseases or immunosuppression. If they cannot be diagnosed early and timely and
effective treatment can be life-threatening .
Head ringworm
1. Definition:
It is a kind of
dermatophytosis that affects the scalp hair follicles. It can usually cause
inflammatory or non-inflammatory hair loss, which mainly occurs in pubertal
children.
2. Pathogenic
microorganisms
There are
three main types of hair in patients with tinea capitis under the microscope,
namely, hair type, hair type and yellow ringworm, reflecting the pattern of
fungi invading the hair shaft, but no matter which mode, the clinical
manifestations are basically hair loss and scales. Often accompanied by inflammation.
3. Clinical
manifestations
The clinical
manifestations of tinea capitis are diverse. The clinical manifestations of
tinea capitis can be divided into 4 types: yellow ringworm, black ringworm,
white ringworm, and pustules.
Yellow ringworm, or tinea
mainly occurs in children, and its typical skin lesions are yellow ringworm scab and yellow ringworm hair. The former is that the spores of yellow ringworm bacteria multiply in the pustules that invade the scalp, forming a circular dish Caused by the yellow scab, the center is slightly concave, the boundary is obvious, 2-5 mm in diameter or larger, a hair passes through the center, can be fused into a piece, or even cover the entire scalp, can smell and an unpleasant rat smell taste. The tissue dissolving action of Xanthomonas can destroy hair follicles, so atrophic scars are often left after the treatment of yellow ringworm, leading to permanent hair loss.
mainly occurs in children, and its typical skin lesions are yellow ringworm scab and yellow ringworm hair. The former is that the spores of yellow ringworm bacteria multiply in the pustules that invade the scalp, forming a circular dish Caused by the yellow scab, the center is slightly concave, the boundary is obvious, 2-5 mm in diameter or larger, a hair passes through the center, can be fused into a piece, or even cover the entire scalp, can smell and an unpleasant rat smell taste. The tissue dissolving action of Xanthomonas can destroy hair follicles, so atrophic scars are often left after the treatment of yellow ringworm, leading to permanent hair loss.
Black
ringworm in children and adults.
At the
beginning, the lesions were mainly papules, which gradually spread to the
surroundings, forming a ring-shaped lesion of the size of a coin. There is a
tendency to heal in the center, and a few scales can be seen. With the course
Progression,
the hair gradually loses its luster, bends and even breaks, so-called
"black spots" marked by broken hairs are formed at the mouth of the
hair follicle, and the intra-articular spores filled with full-length disease
can be seen by microscopic examination, but the disease may be broken at a high
position.
White ringworm:
early ringworm-like skin lesions, marginal uplift, caused
by the spread of papules or blisters/pustules formed by the invading part of
the bacteria to the surroundings at an equal distance, and later evolved into
plaques mainly with scales, without Obvious edge uplift; most or all of the
hair in the plaque is broken 2 to 4 mm away from the scalp, and the outer
periphery is covered with a gray-white bacterial sheath; microscopic
examination shows a pile of densely distributed extracellular spores; sometimes
small "spots.
Pus
tinea:
mainly
caused by some protozoan or soil-friendly dermatophytes, the mechanism is that
the patient produces a delayed allergic reaction to fungal antigens. The clinical manifestations
are obvious inflammatory reactions. The initial occurrence is dense inflammatory
follicle papules and small pustules, which quickly progress to large or larger
bumps and abscesses in walnuts. They are often single, clear, and have a
fluctuating touch. Local hair is loose and easy to remove, and scars can form
after healing.
Fourth, diagnosis and
differential diagnosis
1. Mycological
examination
(1)
Microscopic
examination:
yellow ringworm scab or disease should be
taken for examination. The spores and staghorn hyphae of different sizes filled
with visual field can be seen in the scab. The disease shows the type of the
hair, and the number of hyphae and bubbles in it It is related to the
progression of the disease stage; black ringworm chooses point-like broken hair
or tarnished hair, which can be seen that the intra-articular hyphae fill the
entire hair; white ringworm collects broken hair with a sheath, and the dense
microspores outside the hair are seen embedded in Hyphae can also be seen in
the hair, so tinea versicolor is actually inside and outside the hair.
(2) Cultivation:
The disease,
dander or pus can be taken for routine inoculation and culture. Yellow ringworm
The
uniformly diseased microorganism is Xanthomonas fuliginea, black ringworm is
mainly caused by Trichophyton violaceum, Trichophyton brevis and Trichophyton mentagrophytes,
while tinea versicolor is caused by Microsporum canis and Microsporum gypsum,
Occasionally rust-colored microspores. The identification results of the
bacterial species are decisive for the diagnosis of tinea capitis.
2. Differential diagnosis
This disease
should be distinguished from skin diseases such as scalp seborrheic dermatitis,
dandruff, atopic dermatitis, eczema, pityriasis, psoriasis, alopecia areata,
pyoderma, and trichotillomania. Important indication, and examination
is the key basis.
Treatment
1. The
principle of treatment: "five-character therapy", that is,
"take, wipe, wash, shave, cook". Due to the severe inflammation of
psoriasis, small amounts of glucocorticoids can be taken as appropriate, and
antibiotics should be selected for those with bacterial infection. External
treatment of tinea capitis alone is ineffective, because the medicine is
difficult to reach the hair follicle, so oral antifungal preparations are
needed.
2. The
current gold standard for treatment is still oral griseofulvin. Ordinary
micronized griseofulvin is taken orally at 3 to 15 mg/kg·d in three meals,
because fat meals can enhance absorption; if it is taken ultrafine For
micronized preparations, the dosage should be 10-15 mg/kg·d. Domestic scholars
suggest that the course of treatment is 2 to 3 weeks, while foreign
counterparts believe that at least 6 to 8 weeks. The drug is satisfactory and
safe for most patients, and can be well tolerated by children.
1. For the
capsule preparation, it is not suitable to disassemble and subdivide it
mechanically, so as not to affect the bioavailability. The method of changing
the dose every other day can be used. For example, if the child needs to take
150 mg/d, the first day can be 100 mg, the next day 200 mg, and the next day
100 mg, Rotate in turn.
jock itch
1. Definition:
Tinea and tinea corporis refers to dermatophyte infections on the smooth
skin epidermis. Tinea tinea pedis refers specifically to tinea corporis that
occurs in the groin, perineum, perianal and buttocks.
2. Pathogenic
microorganisms
Dermatophytes
are often parasitic on the stratum corneum of human epidermis, rarely invading
the sub epidermal structure, but in recent years, reports of deep infections of
dermatophytes have increased.
3. Clinical
manifestations
first
appeared as red papules or small blisters, followed by the formation of scales,
and then gradually expanded into a ring-shaped skin lesion with a marginal
uplift and a clear boundary. The center of the skin lesions tended to recede
while the margin was abducted. The lower edge of jock itch is often
significant, and the upper edge is not clear. Scrotal involvement is rare;
ring-shaped lesions are sometimes single, sometimes multiple ring-shaped
lesions can be seen, which can overlap or be scattered, with varying degrees of
itching.
Fourth, diagnosis and
differential diagnosis
Diagnosis
is mainly based on clinical manifestations combined with mycological
examination results.
Treatment
The
affected area should be ventilated and dry. It is mainly used outside the
treatment, and various types of antifungal drugs can be applied. The dosage
forms include
Water,
cream, gel and ointment should be selected according to clinical manifestations
and infected parts. Use fungicidal drugs for short-term
treatment, only 1 to 2 weeks, and fungal inhibitors should be appropriately extended; the generalized lesions can be taken orally
Binafin or itraconazole or fluconazole.
Hand ringworm, tinea
pedis
1. Definition:
Hand ringworm and foot tinea (tinea pedis) refer to dermatophyte infections that
occur on the hands and feet except on the back side.
2. Pathogenic microorganisms
The
pathogenic microorganisms are mainly Trichophyton rubrum, followed by
Trichophyton mentagrophytes and Trichophyton floccus. The special anatomical
part of the palm and plantar part makes it more susceptible to dermatophytes.
It is now tended to be recognized that ringworm has a high genetic
susceptibility, especially keratotic hyperplasia and nails caused by
Trichophyton rubrum Ringworm, genetic factors and environmental conditions are
equally important.
3. Clinical manifestations
Athlete's
foot can be clearly divided into three types clinically, namely impregnated
erosion type, blister type and keratohyperplastic type. Such classification is
closely related to the infected pathogenic microorganisms.
1. Impregnated erosion type:
also known as inter-rubbing type, mainly caused by Trichophyton rubrum,
Trichophyton mentagrophytes and floccus epidermidis, chronic process, clinical
features are mainly sweating, itching, odor, 4. 5 Impregnation and erosion
between toes can sometimes be secondary to bacterial infections, severe cases
can cause lymphangitis, cellulitis or erysipelas.
2. Pimple blister type:
mostly
caused by Trichophyton mentagrophytes, the course is a subacute process on the
basis of a chronic mild disease, the clinical manifestations are itching,
blisters, pustules, sometimes seeing fissures, skin lesions can be from the
inter-toe area Expanding around, this type is easy to stimulate ringworm rash.
1. Keratoproliferative type:
Most of the pathogenic
microorganisms are Trichophyton rubrum, and a few are flocculent
epidermophyton. The clinical manifestations are mainly characterized by like scales and hyperkeratosis. They are often associated with onychomycosis
and have a slow course of disease. It is common to have flaky silvery white
scales on the thickened erythema base spreading over the entire plantar and
lateral margins, often with chapped in winter. Hand ringworm is clinically
mainly blistered and hyperkeratotic. Athlete's foot often affects both feet,
and tinea pedis is usually unilateral.
Fourth, diagnosis and
differential diagnosis
Diagnosis
also needs to combine clinical manifestations with mycological examination. The
dandruff that can scrape the active edge of the skin lesion is directly
microscopically inspected with 10% or 20% KOH film. It is worth pointing out
that negative results cannot completely rule out the diagnosis.
Treatment:
The
principle of is that the medicine and course of treatment should be selected
according to the clinical type and severity of hand, foot and ringworm. For
those with obvious exudation, first apply a wet compress to converge. There is
no obvious erosion. Only erythema scales or papules can be used with various
antifungal creams or gels. For keratotic hyperplasia, keratin exfoliants such
as Wei's ointment or the above creams can be used. Packets, those with
bacterial infections or tendencies should be treated with antibiotics in a
timely manner. Oral antifungal drugs, such as terbinafine , itraconazole, or
fluconazole, should be given to generalized or chronic prolonged types for 2 to
4 weeks.
A real fungal disease
1. Definition:
Dermatophytes, yeasts and molds cause fungal infections of the deck and
sub-nail tissues called onychomycosis. This disease has not received much
attention from doctors and patients because of its slow course, difficult to
cure, and no obvious pain.
2. Pathogenic microorganisms
The
pathogenic microorganisms of onychomycosis include dermatophytes, yeasts and
molds, among which dermatophytes are the most common. This is because
dermatophytes have keratinase, which is more invasive to the keratin-rich deck;
yeast and mold It can also cause nail infection alone, but it is mostly
secondary to nail hydration or trauma, or it can cause a mixed infection with
dermatophytes.
3. Clinical
manifestations
Onychomycosis can be clinically divided into 5 types, that is, distal lateral
sub-nail type, proximal sub-nail type, white superficial type, in-deck type and
full nail damage type.
1. Distal lateral sub mandibular type:
the most common clinical.
Mostly caused by dermatophytes, trichophyton mentagrophytes, epidermophyton
flocculata, Candida and molds can be isolated. The foot is more susceptible,
and the infection begins at the anterior and/or lateral edges of the nail, and
is often accompanied by infection of the adjacent skin. The destruction of the
deck is mainly keratinized hyperplasia, which is manifested by the change of
the nail's color, texture and thickness, and sometimes the separation of the
deck and the nail bed; often the single nail is first affected, and then the
other healthy nails are affected by neglect.
2. Proximal inferior nail type:
The infection starts from the proximal end of
the deck and occurs more frequently in the fingers. It can be combined with
paronychia. At this time, it is mostly caused by Candida infection, and dermatophytes are also detected. There is no obvious
hyperkeratosis on the deck, which can be shown as white spots and uneven
surface, showing a malnourished appearance.
3. White superficial type:
mainly caused by Trichophyton mentagrophytes
and Cladosporium. The diseased nails showed white spots, clear borders,
smoother surface, yellowish color after a long time, and the texture was crisp
and easy to break. Since this type of fungus only invades the upper deck,
external medicine treatment is expected to receive good results.
4. Full nail dystrophy type:
It is actually developed from the above types.
Depending on the pathogenic microorganisms, it can be manifested in different
appearances of the diseased nails, thickened and discolored whole nails, or
incomplete incomplete nails. This type is more common in the elderly or those
with susceptible factors, and treatment is more difficult.
Fourth, clinical
diagnosis
At
present, the laboratory diagnosis of onychomycosis is still mainly through
microscopic examination and cultivation. As long as the hyphae or spores are
found in the debris of the removed nails, the diagnosis is established. The
selection of materials is very critical, which is related to the accuracy and reliability.
Treatment
Now
terbinafine and itraconazole have been widely used in the treatment of
onychomycosis, the new topical drugs amorolfine and ciproterone have also been
on the market, the current problem is how to treat onychomycosis reasonably and
effectively. The newly advocated new concept of treatment of onychomycosis is
individualized treatment and secondly combined treatment.
Deep Fungal Disease
1.
Concept: It is an acute, subacute, or chronic infection caused by Candida. involving the skin, mucous membranes, and internal organs. Candida can be
divided into superficial and deep (viscera) candidiasis
according to the site of candida involvement.
2. Epidemiology:
Candidiasis is widely distributed worldwide. Population epidemiological survey
results show that a large percentage (30% to 50%) of normal people can isolate
Candida from the oral cavity and digestive tract, and the rate of Candida
infection in the reproductive tract of normal women is as high as 20%,
indicating that Candida is a human body One of the normal flora.
3. Causes
There are
many susceptible factors for deep candidiasis, mainly due to various reasons
that impair the immune function of the patient, and the factors that cause the
resistance to decline are:
·
barrier destruction;
·
dysbacteriosis;
environmental changes in the body;
·
immune function Not waiting.
At least 8
species of Candida can cause human infections, among which Candida albicans is
the most common and most pathogenic. There are two sources of infection:
endogenous and exogenous. Deciding whether to get sick depends on the
pathogenicity of the bacteria and the resistance of the host.
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