fungal pathogens

Question 1

GROUP of 3 genuses of fungus that is keratinophilic so can cause disease in hair, skin and nails. slow growing mould that are geophilic, anthrophilic or zoophilic.
(trichophyton, microsporum, epidermophyton)

Answer 1

dermatophytes

Question 2

commonest cause = trichophyton rubrum
interdigital flaking, wetness, itching of feet
when it affects whole foot = ‘mocassin foot’
can get a secondary bacterial infection

Answer 2

tinea pedis / ‘athlete’s foot’

Question 3

4 different types, affects the nails

Answer 3

tinea unguium / onchomycosis / ‘fungal nail disease’

Question 4

commonest cause = trichophyton rubrum
M>W. itching, scaling, red plaques with defined edges, satellite lesions sometimes present. can extend to back and lower abdomen.

Answer 4

tinea cruris / ‘jock itch’

Question 5

caused by trichophyton.
slight inflammation, scaly patches with alopecia, black dots or grey patches, severe inflamm ] large range of symptoms. Might get KERION CELSI (boggy inflamed lesions, zoophilic) or FAVUS (cup shaped crests).
endothrix (spores inside hair shaft), exothrix (outside), favis (hyphae only in hair shaft).
quite severe so many need systemic antifungals.

Answer 5

tinea capitis / ‘scalp ringworm’

Question 6

caused by many types of dermatophytes.
circular, single or many erythematous plaques. may extend from scalp / groin. May cause MAJOCCI’S GRANULOMA = invasion of hair follicle.

Answer 6

tinea corporis / ‘ringworm’

Question 7

what is the treatment for dermatophyte infections?

Answer 7

topical antifungals like terbinafine/ clotrimazole.

systemic antifungals if more severe like griseofulvin / clotrimazole

Question 8

what are the general types of fungal disease?

Answer 8

superficial (hair, skin, nails) - caused by dermatophytes and candida.
subcutaneous (following trauma)
systemic (deep organs) -caused by candida and aspergilllus.

Question 9

what are the 3 main genuses of fungus?

Answer 9

candida
aspergillus
+ dermatophytes (3 genuses = trichophyton, microsporon, epidermophyton)

Question 10

a genus of YEASTS which normally colonise the GIT but can cause oral/ vaginal thrush, skin disease, keratinitis. once it enters the circulation, it can affect any organ and cause systemic disease.

Answer 10

candida spp

Question 11

name the types of oral candidosis ( = candida or oral mucosa)

Answer 11

acute pseudomembranous = users of steroid inhalers, low CD4, younger ppl
chronic atrophic = erythema present , older patients
angular chelitis = red by corners of lips.
chronic hypoplastic = has potential to become malignant.

Question 12

name some risk factors for oral candosis

Answer 12

ABx use - less competition
head and neck cancers treatd by radiotherapy + chemotherapy - less immune there
hospitalisation - more colonisation
HIV/AIDS - immunocompromised

Question 13

candida in the vaginal mucosa. pruritus, burning, ± discharge. Inflammation might extend to the labia majora. happens more often during pregnancy. 10% of people suffer from recurrent infections (due to a subtle immune defect).
most common cause = c.albicans.

Answer 13

candida vulvovaginitis

Question 14

How would you diagnose and treat candida vulvovaginitis (vaginal thrush)?

Answer 14

culture and antifungal sensitivity testing
oral AZOLES e.g. fluconazole (some species of candida are resistant to this).
N.B. DO NOT give this medication to pregnant women (increases the risk of tetralogues).

Question 15

systemic
mainly ppl with HIV (immunocomp).
pain eating and swallowing –> endoscopy and biopsy.

Answer 15

candida oesophagitis

Question 16

candidaemia causes this.
rare.
as a result of IVDU, valve surgery….
fever, weight loss, heart murmer, fatigue

Answer 16

candida endocarditis

Question 17

systemic.
candida in the blood reaches the kidney and lodges in there.
commonest in immunocomp. + premature babies.
causes fever, abdo pain, oliguria, anuria.

Answer 17

renal candidosis

Question 18

ascends from genitals / cathetarisation.
W>M, occurs in DM more often for some reason, damaged urinary tracts.
Hard to manage as antifungals are not secreted in urine.
would usually find candiduria (although this can be clinically insignificant)

Answer 18

urinary tract candida

Question 19

a peritoneal dialysis complication, or bowel perforation –> fever, abdo pain, nausea, vomiting
diagnosed by peritoneal fluid.

Answer 19

candida peritonitis

Question 20

disseminated.
occurs in leukaemia due to neutropenia –> when the neutrophils recover, yeast lodges in the liver and spleen causing abscesses (Bull’s eye sign), fever, liver function, disturbance.
antifungals can be ineffective as dead fungus can still trigger inflammation.

Answer 20

candidosis

Question 21

rare

remove lines, start antifungals, check heart and eyes

Answer 21

candidaemia

Question 22

a genus of MOULD. produces airborne species which everyone gets exposed to via inhalation. causes aspergillosis if there is a reaction to it when it is inhaled.
important species = -niger, -flavus, -terreus

Answer 22

aspergillus spp

Question 23

a fungal ball in the lung cavity
common in conditions that cause cavitation like TB, sarcoid.
often silent and fine, until they break up!!!! can be fatal so must be resected.

Answer 23

aspergilloma

Question 24

allergic reaction to aspergillus –> IgE reacts

treat with antifungals and steroids

Answer 24

severe asthma (with fungal sensitisation)

Question 25

wheezing, breathlessness, loss of lung function, bronchiectasis, airway inflammation caused by IgG and IgE reaction to aspergillus. sputum culture + IgE test.
treat with antifungals and steroids.

Answer 25

allergic broncho-pulmonary aspergillosis

Question 26

a type of COPD caused by aspergillus. respiratory symptoms - coughing, SOB, wheeze, chest pain. diagnose with a sputum culture and IgG test.

Answer 26

chronic pulmonary aspergillosis

Question 27

occurs in immunocomp people.
e.g. invasive pulmonary aspergillosis, invasive pulmonary sinusitis.
angioinvasion of lung tissue. dissemination to extrapulmonary in 25%.
HALO + AIR CRESCENT signs on CT. even with antifungals, there is a poor prognosis.

Answer 27

invasive aspergillosis

Question 28

how do you diagnose and treat aspergillosis?

Answer 28

culture + serology (look for the antibodies if immunity is fine, but if not then look for the antigens)
imaging