Infectious Flashcards
What is condyloma acuminatum
Genital warts(HPV 6 and 11 )
Infection of skin upper medial scrotum?
Tinea cruris - jock itch
Moisture, warm weather, wet clothes, tight clothes
Name 7 causes urethritis and urethral discharge
- Most commonly STI: neisseria gonorrhoea or chlamydia trachomatis. May rarely be ureaplasma urealyticum, trichomonas vaginalis, mycoplasma genitalium.
- urethral catheter
- urethral instrumentation
- urethral calculus
- urethral tumour
- chemical irritation
- systemic illness: Reiter’s syndrome (reactive arthritis)
Classification of urethritis and major differences (5) organism, complications, incubation, discharge, symptoms
Gonococcal vs non-gonococcal
• neisseria gonorrhoea vs chlamydia trachomatis, rarely ureaplasma urealyticum and trichomonas vaginalis
• complications urethral stricture 20 years later,epidydimitis, infertility vs epidydimitis (commonest cause heterosexual men), urethral stricture
• incubation 1-7 days us 1-5 weeks
• urethral discharge thick, purulent, yellow-brown vs scanty and watery
. Both dysuria and urethral itching
Diagnosis gonococcal urethritis?
Gram stain from urethral swab show gram-negative intracellular diplococci on microscopy
Diagnosis non- gonococcal urethritis?
- Gram stain difficult but show >4 PMN /oil immersion field with no evidence N gonorrhoea
- best to do chlamydia monoclonal antibody test from serum sample
Treatment gonococcal urethritis?
Ceftriaxone 250 mg IM stat or ofloxacin
And treat for chlamydia (30% with gu also have chlamydia): azithromycin 1 g po or doxycycline 100 mg po bd x 7 days
Treatment non-gonococcal urethritis?
Doxycycline 100 mg po bd X 7 days
Or azithromycin 1 mg oral stat
How confirm diagnosis urethritis?
Urine microscopy show >4 WBC / HPF of urethral secretion or >15 WBCs / HPF of first voided 10-15 ml urine (centrifuged)
Define Fournier’s gangrene
Necrotising fasciitis of perineum
Fulminating infective process spreading rapidly along fascial planes, causing thrombosis of subcutaneous blood vessels and gangrenes of overlying skin
Name 6 risk factors necrotising fasciitis of perineum
- Chronic alcoholism
- diabetes!
- immunosuppression: hiv/aids, steroid treatment
- chemo for malignant disease
- transplant patients
- malnutrition
Where can sources of infection for Fournier’s gangrene be? (6)
Urogenital
• urethral stricture
• indwelling urethral catheter
• urethral injury
Anorectal
• perianal/ ischiorectal abscess
• routine anorectal procedures
Cutaneous infection/ trauma
Name the bacteriology of Fournier’s gangrene (6)
Polymicrobial infection with aerobes and anaerobes. Commonly isolated species: • enterobacteria esp e coli, . Bacteroides • streptococci • staphylococci • peptostreptococci • clostridia (Normal flora)
Cause of tissue destruction in necrotising fasciitis of the perineum?
• Ischaemia
• synergistic action of various bacteria
• production of proteins and enzymes by organisms:
-Hyaluronidase → tissue destruction
-Coagulase → interference with phagocytosis
Clinical features Fournier’s gangrene? (8)
Early
• pain, erythema, swelling of scrotum
• pyrexia
Late • cyanosis/blistering of skin (bullae) • crepitus • obvious cutaneous necrosis • extension to ant abdominal wall and thighs • septicaemia Mortality 20%
Name 5 factors associated with increased mortality in necrotising fasciitis of perineum
- Increased age
- anorectal infections
- delay in diagnosis and treatment
- debility
- diabetes!
Management Fournier’s gangrene? (5)
• Aggressive haemodynamic stabilisation
• iv broad spec antibiotics triple therapy (PAM)
- penicillin for gram positive
-Aminoglycoside eg amikacin for gram negative, or cephalosporin third generation
- metronidazole for anaerobes
• urgent surgical debridement of areas of overt subcutaneous necrosis, may need multiple
- testes may need to be put in subcutaneous “pockets” in thighs
- split skin grafts for large defects later
• May need suprapubic cystostomy or colostomy diversion
• Treat underlying cause
• adequate nutrition
How does Fournier’s gangrene spread? (7)
Via fascia. Along fascia plane
• Infection Colles superficial perineal fascia → Buck deep. and Dartos superficial fascia → penis and scrotum
• Colles → Scarpa fascia (Anterosuperior to Colles , cover abdominal and thoracic muscles, extend to clavicles) And campers (Loose areolar fascial layer deep to skin abdominal wall but superficial to scarpa, continuation colles superolateral ) → abdominal wall
• Colles fascia attached to perineal body and urogenital diaphragm posterior , pubic rami and fascia lata laterally, limiting progression in these directions.
• Testicular involvement rare: testicular arteries originate directly from aorta thus have separate blood supply.
Differential diagnosis Fournier’s gangrene presentation? (6)
- Scrotal cellulitis
- scrotal abscess
- Strangulated inguinal hernia
- penile gangrene rare
- scrotal gangrene- complication of vasculitis
- pyoderma gangrenosum- rare skin condition
Treatment bilharzia?
• Praziquantel 4o mg per kg, repeat urine microscopy 1 month later to confirm ova eradication
. Surgery for complications
-Cystectomy for bladder carcinoma
- ureteric reimplant for ureteric stricture
Define UTI
Infection above internal sphincter of bladder
Below that called prostatitis, urethritis etc
Treatment UTI? (7)
- General measures: admit if toxic, complicated, vomiting; iv fluids if inadequate hydration; blood culture if high temperature
- simple, uncomplicated:
- tmp-smx (bactrim) (sulfonamides) 160/800mg po bid for 3 days or
- nitrofurantoin 100 mg po bid for 5 days or
- Fosfomycin
• complicated
- Fluroquinolones: ciprofloxacin! (ciprobay!) 1g po daily 2-3 weeks; ofloxacin, or
- Aminoglycosides: gentamicin (garamycin!) with ampicillin ; amikacin
- cephalosporins: ceftriaxone 1-2g iv q24h for 2-3 weeks; cefotaxime (claforan!)
- co-amoxiclavalanic acid (augmentin) - not for empirical, E. coli resistant!
Treatment syphilis?
Benzathine penicillin 2.4 million units IM stat
Or doxycyclycline if allergic
Treatment chancroid?
Erythromycin or
Co-trimoxazole or
Ceftriaxone 250 mg IM stat
Treatment granuloma inguinale?
Doxycyclicine 100mg 2x/day or
Co-trimoxazole 2 tabs 2x/day
Until lesions resolved (at least 3 weeks)
Treatment hsv?
Acyclovir 200-400 mg 5x/day for 7-10 days, or until clinical resolution
Must start within 2-3 days appearance of lesions
Treatment condyloma acuminata? (8)
Medical
• salicylic acid
• podophyllin (protect normal skin with Vaseline) (chemical cauterization)
• trichloroacetic acid
• imiquimod! (Aldara)
• interferon
• 5 fluorouracil ! - contraindicated on mucosa, too toxic
Surgical • cautery: electro-coagulation • surgical excision eg circumcision • cryotherapy: liquid nitrogen, histofreezer • laser
Which other conditions are associated with condyloma acuminata?
Peri -anal warts
Cervical cancer
( hpv )
Clinical presentation bilharzia? (5)
• Cercarial dermatitis (“swimmers itch”) at site of cercariae penetration:pruritic maculopapular eruption 3-8 hours after exposure, last hours to days.
• katayama fever: in populations not previously exposed, not endemic. Allergic reaction to schistosomes in liver laying eggs. Present with fever, jaundice, hepatosplenomegaly 3-4 weeks after infection
• urinary schistosomiasis
- terminal haematuria! Classic
- frequency and dysuria
- may present with complications, like squamous cell carcinoma of bladder
Diagnosis schistosome haematobium? (4)
• Terminal urine! Most ova excreted middle of day and after exercise:microscopy for ova with terminal spike
. FBC: eosinophilia in acute phase
• IVP /eug:
-Calcifications bladder wall, distal ureters, seminal vesicles
- dilated ureters
-Filling defect bladder due to bilharzia papule, blood clot, carcinoma
- small bladder capacity
• serology ELISA to screen, cystoscope if unsure or complications
Where does schistosome mansoni live?
Intestinal schistosomiasis
