Infectious Disease Flashcards
1
Q
influenza
A
- orthomyxovirus
- transmission: resp droplets, winter months
- sxs: rapid onset of fever, chills, malaise, myalgia (legs or lumbosacral area), fever, HA (generalized or frontal), nonproductive cough (may last more than 1 wk), ocular signs/sxs (pain w/ motion of eyes, photophob, bruning of eyes), sore throat, +/-N
- signs: cervical LAD, rhonchi, wheezes, scattered rales
- dx: RT-PCR = most sensitive and specific (can differentiate subtypes and detect avian flu
- tx: supportive care (tylenol or NSAIDs . for HA, myalgias, fever; no cough suppressants, neruaminidase inhib: zanamivir or oseltamivir for flu type A and B → reduces sxs by 1-1.5d if started w/in 2 days of onset
2
Q
First disease: measles
A
- AKA rubeola
- incubation: 2wk
- sxs: prodromal (malaise and anorexia), then high fever and lethargy (4-7d), 3 Cs Triad (cough, coryza (runny nose, congestion), conjunctivitis), rash on day 3
- signs: Koplik spots (blue/gray spots on buccal mucosa), blanching erythematous macules and papules on face at hairline, sides of neck, and behind ears (coalesce into patches and plaques on trunk and extrems (palms/soles) lasts 5-7d
- dx: clinical, IgM titer, IgG, viral cx from throat and nasal swab, RT-PCR
- tx: ibuprofen, fluids, vitA
- complications: PNA, OM, endcephalitis
3
Q
second dz: scarletina
A
- S. pyogenes, group A strep
- transmission: resp droplets, common in overcrowded places
- sxs: fever, abd pain, HA, pharyngitis, rhinorrhea, rash 12-48h after onset of fever (erythem patches below ears, on neck chest and axilla, dry ROUGH TEXTURE OF FINE SANDPAPER, blanchable, disseminates to flexural areas (axillae, pop fossa, inguinal folds), pastia lines: confluent petechiae in skin creases, neck, antecubital, axilla, groin
- signs: enlarged ant cerv lymph nodes, red scattered petechiae on soft palate, STRAWBERRY TONGUE (heavily coated with white membrane with edematous red papillae)
- dx: clinical, CBC, leukocytosis with left shift, cx or rapid strep test, antistreptolysin titer
- tx: calamine, tylenol, amox, macrolide
- prognosis: desquamation begins 7-10d after resolution of rash
- complications: rheumatic fever, septicemia, vasculitis, hepatitis, OM, PNA, osteomyelitis, glomerulonephritis
4
Q
third disease: Rubella
A
- blueberry muffin baby, german measles
- Rubella virus (RNA virus rubivirus), 2-3wk incubation, prodromal phase absent in children
- transmission: droplet
- incubation period: 14-19d
- sxs: mild URI, low grade fever, macular rash day 1, face → trunk → limbs, arthralgia
- signs: postauricular, postcervical, and occipital nodes (tender, generalized), forscheimer sign (enanthem of soft palate)
- clinical dx
- tx: ibuprofen, fluids, contageious for 7d after rash onset
- complications: PDA, pulm art stenosis, aortic sten, ventricular defects, thrombocytopenic purpura w/ purple macular lesions, cataracts, retinopathy, sensorineural deafness
5
Q
Fifth disease: erythema infectiosum
A
- slapped cheek syndrome
- parvovirus B19, 4-14d incubation
- transmission: aerosolized resp droplets, mother to fetus
- sxs: mild URI, HA, pharyngitis, itching, coryza, abd pain, arthralgias, low fever, 1wk later slapped cheek (nasal perioral, and periorbital sparing), lacy reticular rash on prox extrems and trunk, palms and soles spared
- complications: arthritis, anemia, fetal hydrops
- clinical dx
- tx: ibuprofen, fluids
- NOT INFECTIOUS when rash occurs, may attend school or childcare (only infxous in mild URI phase (2-3d))
6
Q
sixth disease: Roseola
A
- HHV 6B or 7, 5-15d, MC in 9-12mo olds
- sxs: high fever x3-4d +/- febrile seizure, after 3d fever dissapates and rash occurs (small pink blanchable rash - morbilliform, nagayama spots (red papules on soft palate and base of uvula))
- dx: CBC, UA, blood cx, CSF exam, roseola IgM
- tx: ibuprofen, fluids
- complications: febril seizures
7
Q
Ebstein-Barr dz
A
- caused by epstein-barr virus (rarely CMV), adolescents, college students, or military recruit
- transmisison: saliva, 90% adults infected previously are carriers, lifelong immunity w/ 1 infxn
- sxs: fever, LAD, pharyngitis → fever resolves in 2 wks, sore throat, malaise, myalgias, weakness
- signs: LAD, posterior cervical, tonsillar, enlarged, painful, tender; pharyngeal erythema and/or exudate, splenomegaly, maculopapular rash, hepatomeg, palatal petechiae and periorbital edema
- dx: monospot, WBC count with diff, transaminitis, EBV specific Ab, peripheral smear shows lymphocytic leukocytoisis with large, atypical lymphocytes
- tx: supportive, short course steroids, avoid sports 3-4wks (SPLENIC RUPTURE)
- complicaitons: hep, meningoencephalitis, Guillain Barre, splenic rupture, thrombocytopenia, URTI
- DONT GIVE AMOX or AMP → can cause maculopap rash
8
Q
atypical mycobacterial disease
A
- etiology: mycobacterium avium complex (MAC), M. fortuitum complex, M. kansassi
- no airbonrne contact, noncontagious
- sxs: indolent or subacute course
- MC sx = fever, cough, SOB, fatigue, weight loss, hemoptysis
- unilateral cervical, submandibular, or preauricular lymphadenitis - painless and firm, no warmth and well circumscribed
- but fever and systemic sxs are minimal or absent
- dx: Runyon criteria: nonchromogens (MAC) - produce no pigment, rapid growers; produce visible growth on standard agar in 1 wk, which usually takes 2
- Ziehl-Neelsen: AFB +
- PPD: + or -
- AFB smear and cx
- tx: surgical excision - if excision is not possible or there is a recurrence of dz, antimycobacterial drugs may be used = clarithromycin, azithromycin, rifampin and rifabutin, ethambutol
9
Q
pinworms
A
- transmission: fecal-oral; humans are ONLY natural host
- RF: close living quarters, crowding
- MC: children 5-10, occurs in both temperate and tropical climates, MC helminthic infxn in the US
- Pathogen: enterobius vermicularis
- sxs: perianal pruritis at night, abd pain, N/V
- dx: pinworm paddle test - place cellophane tape on anus and microscopically examine for ova (performed at night or first thing in the morning prior to bath, eggs = bean shaped)
- tx: one of the following: albendazole, mebendazole, pyrantel pamoate (AE: anorexia, N, V, cramps, D, neurotoxic effects, inc LFTs, okay for pregnant women)
10
Q
varicella infxn
A
- chickenpox
- incubation: 14d
- sxs: fever, rash on face/scalp, moves to trunk/extremities
- signs: papules and vesicles, crusts “dew drop on a rose petal”
- dx: tzanch smear to confirm herpes simplex, varicella, and zoster infxn
- tx: valacyclovir decreases incidence of varicella PNA
11
Q
hand-foot-and-mouth dz (herpangina)
A
- coxsackie virus group A type 16
- sxs: low fever for 24-48hrs, sore mouth or throat, fatigue, malaise, URI +/- abd pain
- signs: dehydration, petechiae, vesicular or papular lesions on mouth, palms and soles that become shallow ulcers in 3d (can also involve buttocks, genitalia)
- dx: clinical dx
- tx: adequate fluid intake (cold liquids), avoid spicy or acidic substances, ibuprofen (motrin), magic mouthwash
- prognosis: virus clears in 10d
12
Q
pertussis etiology, RF, and sxs
A
- Bordetella pertussis - G- coccobacilus, highly contagious during catarrhal stage, transmitted via resp droplets
- incubation period = 7-10d, more than 50% of cases occur in adolescents and adults - serve as a reservoir for infxn of infants and children
- sxs:
- catarrhal stage (1-2wk): insidious onset of sneezing, rhinorrhea, loss of appetite, malaise, hacking cough at night (most infxs state)
- signs: gagging, cyanosis, inc work of breathing, sweating
- paroxysmal stage (2-8wk): spasms of rapid coughing fits during expiration followed by deep, high-pitched inspiratory “whoop”, last several minutes, posttussive emesis or syncope
- convalescent stage: dec in frequency and severity of paroxysms, begins 4wk after onset of cough and lasts several wks
- catarrhal stage (1-2wk): insidious onset of sneezing, rhinorrhea, loss of appetite, malaise, hacking cough at night (most infxs state)
13
Q
pertussis dx and tx
A
- dx: most accurate during catarrhal phse, dx mostly clinical (cough >2wk required), microbiological testing required to ocnfirm; culture and PCR assays if cough for 2-4wk, cx = GOLD STANDARD, must use dacron or calcium alginate swab to obtain from posterior nasopharynx; serology = alternative to cx for cough after 4+wk, WBC count = elevated, lymphocytosis
- tx: abx during catarrhal phase (dec severity and duration of cough, indicated for cough <3wk or 6wk for preg women, health care workers, or child care workers)
- macrolides (azithro, clarithro, erythro)
- macrolide intolerant (bactrim DS, ampicillin)
- prophylaxis: single Tdap booster for adults 16-64y, postexposure prophylaxis for close contacts
- complications: infxn (PNA, otitis media)
14
Q
pertussis tx based on age
A
- infants <1mo: azithro x5d, erythro (both are associated with inc risk hypertrophic pyloric stenosis)
- infants and children >1mo: azithro x5d, clarithro x7d
- children >2mo: macrolides, bactrim
15
Q
herpes simplex stomatitis: etiology, sys
A
- MC manifestation of primary HSV infxn in childhood
- ulcerative lesions on gingiva and mucous membranes of mouth with perioral vesicular lesions
- MCC: HSV1 - mainly children 6mo-5y
- transmission: direct contact with infected oral secreations or lesions (sxatic or asxatic individuals with primary or recurrent HSV)
- incubation: 2d-3wk (mean: 4d)
- sxs: prodrome (fever, anorexia, irritability, malaise, sleeplessness, HA), painful lesions in oral cavity or perioral area
- signs: red, edematous marginal gingivae that bleed easily, clusters of small vesicles (turn yellow after they rupture, red halo, coalesce to form large, painful ulcers, involve buccal mucosa, tongue, gingiva, hard palate, pharynx)
- associated: halitosis, refusal to drink, anorexia, fever, arthralgia, HA, submandibular or cervical LAD
