DERM: Intro to Maculopapular Rash I & II Flashcards
define “viral exanthem”
widspread maculopapular rashes that are accompanied by systemic sx of inflammation
what are the childood infections that cause viral exanthems?

which enteroviruses cause exthanthems?
- Cocksackie A
- echovirus
which childhood viral infection causes nonspecific exanthems?
what does this mean?
- echovirus 9
- echovirus 16
(enteroviruses)
= means there are no vesicles
enterovirus exanthem - pathogenesis
start in the GI tract -> progress to rest of body
enterovirus exanthem - presentation
cocksackie A, echovirus
- systemic
- prodrome
- major: GI sx PRECEDES development of rash
- possible respiratory tract sx
- skin: rash that is
- follows GI sx
- mild macular / maculopapular
- non-pruritic
- 1-3 days (fleeting)
enterovirus exanthem - epidemiology
- demographics
- transmissions
- means of spread
- other
- mostly young infants
- transmitted by saliva & feces (fecal oral)
- spread: _multiple family member_s may be infected concurrently
- most common childhood rash in the summer / fall
enterovirus exanthem - complications
rarely, to meningitis / encephalitis (HA)
parvovirus B12 exanthem - pathogenesis
(erythema infectiosum
virus infects erythroid progenitor cells -> leading to anemia
parvorirus B19 exanthem - presentation
erythema infectiosum
differ in child vs adult:
- child:
- systemic: nonspecific
- skin: “slapped check rash”
- starts on cheek - typically as child is feeling better
- +/- pruritis
- lasts 1-3 weeks
- often waxes / wanes (relapses)
-
adult
- systemic: acute polyarthritic sx common
- skin: rash rare
parvovirus B12 exanthem - epidemiology
- demographics
- transmission
- infectivity
- other
erythema infectiosum
- m/c in school age children
- transmitted via nasal/salivary droplets
- can cross placenta & rarely cause anemia (TORCH dz)
parvovirus B12 exanthem - complications
- acute asplastic crisis (adults) severe aplastic anemia that can laed to CHF, bone marrow necrosis, ect.
-
neonatal erythema infectiosum (neonates only)
- asplastic anemia
- hydrops fetalis
rubella exanthem - pathogenesis
german / 3 day measles
virus replicates in the URT/cerivcal lymph nodes then disseminates -> creates virus-Ab complexes in skin
rubella exanthem - presentation
german measles, 3 day rash
- systemic
- prodrome ONLY in adults, precedes rash
- polyarthritis in 50% of women
- forcheimer spots: petechial hemorrhage on soft palate
- rash
- non-confluent - widely spaced, discrete lesions
- starts on face -> descends (& fades on face)
- lasts up to 3 days
rubella exanthem - epidemiology
- demographics
- transmission
- infectivity
- other
- all ages affected
- transmitted by droplet inhalation
- can cross placenta (TORCH dz)
- rare in US d/t vaccine
rubella - complications
= congenital rubella syndrome (CRS)
-
classic triad: deafness + eye issues + CDH
- deafness
- eye abnormalities - cataracts, glaucoma, retinopathy
- congenital heart disease (“blue baby)
- blueberry muffin rash (purpura)
- growth restriction - low birth weight / microcephaly
- CNS abnormalities - retardation, behavioral disorders
describe the presentation of CRS
- classic triad: deafness + eye issues + CDH
- blueberry muffin rash (purpura)
- growth restriction - low birth weight / microcephaly / radiolucent bone dz
- CNS abnormalities - retardation, behavioral disorders

measles exanthem - pathogenesis
rubeola
paramyxovirus infects leukocytes/lymphatic tissue -> producing multinucleated giant cells (warthin-finkeldey cells) in lymph nodes

identify

warthin-finkeldey cells
mutli-nucleated giant cells resulting from paramyxovirus-infected leukocytes / lymphatic tissue
measles exanthem - presentation
- systemic: prodrome =
- photophobia
- koplik’s spots: white lesions of buccal mucosa opp. molars
- C-triad: cough + coryza + conjuncitivits
- HA
- otitis media (infants)
-
skin: rash
- onset follows fever but overlaps with it
- starts at hairline & descends slowly
- mildly pruritic
- petichial lesions on mucosa
measles exanthem - epidemiology
- demographics
- transmisision
- infectivity
- other
- n/a
- direct contact / droplets / fomites
- highly contagious
- generally rare in US due to vaccine
what are these and what exanthem are they indicative of?

koplik’s spots
measles (rubeola)
measles exanthem - complications
several - pneumonia is key (m/c cause of death d/t measles)
measles
- prognosis
- therapy
- prevention
- prognosis - inc mortality d/t complications (pneumonia m/c). complications indicator = inc risk of complications w/ fever persistence after the 4th day of the rash \
- therapy
- vitamin A
- ribavirin
- prevention - MMR vaccine
rosaela infantum exanthem - pathology
HHV-6 results in antibody-antigen complex formation -> rash
roseola infantum exanthom - pathologenesis
HHV-6B (sometimes HHV-7) causes antibody-antigen complex formation -> rash
roseola infantum - presentation
- systemic: sudden high fever then rapid defervescence followed by a surprise rash
- in infants: cause cause febrile seizures
- skin:
- a “surprise rash” that
- follows rapid defervescence (decline in fever with no overlap)
- is maculopapular
- along with Nagayama spots: small, erythematous papules on the soft palate (uvula)
- a “surprise rash” that
roseola infantum exanthem - epidemiology
- demographics
- transmission
- infectivity
- other
- kids 6 mos - 2 years (infants)
- transmission via:
- saliva
- genetic: integration of HHV-6 intoparent chromosome (congenital “roseola”)
roseola infantum exthanthem
- diagnosis
- prognosis
- therapy
- diagnosis: presentation usually sufficient
- prognosis: typically self limiting, febrile seizures in infants can inc morbidity
- therapy: avoidance, no vax
scarlet fever exanthem - pathology
streptococcus pyogenes express pyrogenic (fever causing) exotoxins A, B and C -> induces a type IV hypersensitivity reaction
scarlett fever exanthem - presentation
s. pyrogenes
- systemic prodrome
- abrupt onset of sore throat + fever
- sore throat = pharyngitis / tonsillitis
- but, no other upper respiratory signs
- tongue: either
- STRAWBERRY TONGUE - bright red
- WHITE STRAWBERRY TONGUE - yellowish white coating
- abrupt onset of sore throat + fever
- skin: sandpaper rash + pastia’s lines + circumoral pallor + superfiial desquamation
-
sandpaper rash - confluent, punctate papules that
- blanch under pressure
-
are concentrated in
- neck
- axilla
- groin
- pastia’s lines - peteiae in creases
- circumoral pallor (red cheeks + pale around mouth)
- superficial desquamation of palms & soles
-
sandpaper rash - confluent, punctate papules that

scarlet fever exanthem - complications
= s. pyogenes
- rheumatic fever (type II hypersensitivity)
- glomerulonephritis (type III hypersensitivity)
tx of scarlett fever?
penicillin G
identify this feature & explain its significance

pastia’s lines: petichiae in creases
seen in scarlett fever exanthem (s. pyogenes)
what childhood viral exanthem do these signs indicate?

scarlett fever
- strawberry & white strawberry tongue = systemic
- desquamation of palms = skin
which childhood viral exanthems are nationally notifiable disease?
- rubella (rubella virus)
- measles (paramyxovirus)
which childhood viral exanthems are TORCH disease?
- erythema infectiosum (parvovirus B19)
- rubella
differentiate the key differences between the skin presentations of each childhood viral exanthem
- erythema infectiosum (parvovirus B19)
- slapped cheeks
- reticulate (lacy) body rash
- enterovirus rash: descenending from face down
- rubella (german / 3-days measles): descending from face down
- measles:
- kopliks spots
- descending rash from harline down
- goes from blanching -> non-blanching
- roseola infantum
- ”surprise rash” (on trunk) following rapid defervescence
- scarlett fever
- sand-paper rash (punctate, confluent papules) on neck + axilla + groin
- circumforal pallor
- pastias lines
- post-rash desquamation on palms & soles
which childhood viral exanthem can cause postauricular lymph node enlargement?
rubella
which childhood viral exanthem is the most common infection of summer / fall?
enteroviruses (cocksackie A and B)
which childhood viral exanthems involve no / short prodrome ?
- erythema infectiosum (parvovirus B12)
- enteroviruses
- rubella
EER - extra extra rapid
tinea versicolor - pathogenesis
= pityriasis versicolor (cutaneous malsseziasis)
- malassezia sp (a dimorphic fungi) metabolize lipids to generate acids that can damage melanocytes causing -> hyperpigmented or hypopigmented lesions

tinea versicolor presentation
malasseziasis sp
- skin: lesions on upper trunk that are
- HYPOPIGEMENTED (white-ish) or HYPERPIGMENTED (brown)
- “branny” - scaly, non-blanching

tinea versicolor - diagnosis
- 10% KOH treated scin scraping: “spaghetti & meatball appearance”
- wood’s lamp: shows yellow/orange luminescence

tinea versicolor - summary
- pathogenesis
- demographics
- presentation
- treatment
- pathogenesis malassezia sp (a dimorphic fungi) metabolize lipids to generate acids that can damage melanocytes
- demographics
- m/c in tropical environments
- repeated overgrowth in - oily skin or I/C
- presentation: HYPOPIGEMENTED (white-ish) or HYPERPIGMENTED (brown) lesions that are scaly & non-blanching
- treatment: anti-fungals

identify

spaghetti & meatbals appearance from KOH stain
dx of tinea versicolor (malasezzia sp fungi)
tinea versicolor - demographics
- m/c in tropical environments
- repeated overgrowth is m/c in people with
- oil skin
- weak immune system
tinea versicolor - tx
topical anti-fungals
toxic shock syndrome (TSS) - pathogenesis
- infection w/ s. aureus > strep pyogenes, which release pyogenic superantigens that act as T-cell mitogens -> cytokine strom -> high fever
- s. aureus: TSST-1 & enterotoxins (enterotoxin = also cause GI sx)
- s. pyogenes: exotoxins & poss M-protein
toxic shock syndrome (TSS) - demographics
s. aureus > s. pyogenes
- generally very rare in US
- though - is m/c in individuals that are negative for anti-TSST-1 antibodies & are unable to make any after being exposed
toxic shock syndrome - presentation
s. aureus > s. pyogenes
- systemic:
- sudden, rapidly progressing fever that can progress to SHOCK: HYPOTENSION + tachycardia / tachypenea
- GI sx if s. aureus
- skin :erythyematous, macular rash + elements resembling scarlett fever, esp if s. pyo
- desquamation of palms & soles
- strawberry tongue
- if so pyo: sandpaper rash
toxic shock syndrome (TSS) - dx
s. aureus > s. pyro
- must meet the following criteria to fit CDC definition:
- fever of 102 F or greater
- rash that is: macular & erythematous OR scarlittiniform (sandpaper)
- HYPOtsn: SBP < 90 or orthostatic drop in SBP > 15 mmHg
- at least 3 major organs involved
toxic shock syndrome (TSS) - treament
- abx: nacillin or oxicillin
- TREAT SHOCK
TSS - summary
- pathogenesis
- demographics
- presentation
- diagnosis
- treatment
- pathogenesis: infection w/ s. aureus > strep pyogenes, which release pyogenic superantigens that act as T-cell mitogens -> cytokine strom -> high fever
- s. aureus: TSST-1 & enterotoxins (enterotoxin = also cause GI sx)
- s. pyogenes: exotoxins & poss M-protein
- demographics: generally very rare in US, but m/c in indiivduals negative for anti-TSST-1 Abx
- presentation:
- systemic:
- sudden, rapidly progressing fever that can progress to SHOCK: HYPOTENSION + tachycardia / tachypenea
- GI sx if s. aureus
- skin :erythyematous, macular rash + elements resembling scarlett fever, esp if s. pyo
- desquamation of palms & soles
- strawberry tongue
- if so pyo: sandpaper rash
- systemic:
- diagnosis: must meet the following criteria to fit CDC definition: 4
- fever of 102 F or greater
- rash that is: macular & erythematous OR scarlittiniform (sandpaper)
- HYPOtsn: SBP < 90 or orthostatic drop in SBP > 15 mmHg
- at least 3 major organs involved
- treatment: nafcillin / oxicillin + TX shock
meningococcemia - pathogenesis
neisseria meningitidis (gram - diplococci) releases lipooligosacharide (LOS) endotoxin, leading to -> vasculitis / localized thrombohemorrhaghic lesions
meningococcemia - demographics
- infants
- teens
- complement deficient: C5, C6, C7 or C8
leptospirosis
- pathogenesis
- trasmission
- presentation
- prognosis
- treatment
= aka weil’s syndrome:
- pathogenesis: leptospirosis (spirochete with hooked ends) reside in kidneys & lead to vasculitis
- transmission: exposure to urine / urine contaminated water from infected mammals
- presentation:
- macular rash -> purpura
-
weil’s triad: JAUNDICE + ACUTE KIDNEY INJURY + HEMORRHAGE
-
hemorrhage:
- pulmonary hemorrhage
- subconjunctival hemorrhage
- epistaxis
- purpura
-
hemorrhage:
- prognosis:
- self limiting except in unborn fetus (> 50% mortality)
- better if there is NO juandice
- treatment: Abx (prevention with doxycyline)

identify & explain significance

= leptospirosis:
- spirochete with hooked ends
- contracted via contact w/ urine from infected mammals
- causes:
- weil’s triad: jaundice + acute kidney injury + hemorrhage
- hemorrhage =
- purpura
- subconjunctival hemorrhage
- pulmonary hemorrhage
- hemorrhage =
- weil’s triad: jaundice + acute kidney injury + hemorrhage
- prognosis better when there is NO jaundice
meningococcemia - presentation
- systemic: nonspecific prodrome
- skin: non-blanchng macules & petichiae that
- begin on trunk & legs then spreading to areas where pressure is applied
- can progress
- purpura
- ecchymosis with central necrosis (confluent purpura)
meningococcemia - complications
- septic shock
- meingitis
- disseminated itravascular coagulation (DIC)
- waterhouse-friedrichsen syndrome
meningococemia - treatment
- penicillin G / ceftriaxone: NECESSARY, OR IS FATAL
-
prevention with menACYW vaccine: meningococcal conjugated polysaccharide vaccine
- note: booster & menB serotype given during epidemics
rat-bite fever
- pathogenesis
- presentation
- treatment
- d/t one of two gram negative bacteria that cause hematogenous dissemination:
- streptobacillary:- d/t streptobacilus monoformis:
- microaerophillic
- pleomorphic
- filamentous rod
- spirillary: d/t spirillum minus:
- aerobic
- bipolar-flagellated spiral
- streptobacillary:- d/t streptobacilus monoformis:
- presentation:
- systemic:
- polyarthralgia
- relapsing fever at irregular intervals
- skin: purpuric maculopapular rash -> small pustules on palms & soles
- systemic:
- treatment: penicillin G
what are the two etiologic agents of rat-bite fever and
- how are they different?
- which one causes RBF in the US?
- streptobacillary (streptobacilus monoformis) - only form seen in the US
- microaerophillic
- pleomorphic
- filamentous rod
- spirillary (spirillum minus)
- aerobic
- bipolar-flagellated
- spiral
secondary syphyllis
- pathogenesis
- transmission
- presentation
- diagnosis
- prognosis
- treatment
- pathogenesis: treponema pallidum (spirochete) causes a chancre at innoculation site
- transmission:
- sexually
- congenital (TORCH dz)
- presentation:
-
rash:
- maculopapular lesions on the palms & soles are non-pruritic
- mucutaneous lesions ton oral, genital, anal
- condyomata latum: wart like, moist
- alopecia
-
rash:
- diagnosis:
- VDLR/RPR, then FTA-ABS
- darkfield microscopy - shows spirochete
- treatment: penicillin G
erlichiosis
- pathogenesis
- presentation
- diagnosis
- treatment
- pathogenesis: one of two obligate intracellular pathogens is transmitted via lone star tick bite
- erlichiae chaffeensis: infects monocytes - human form
- erlichiae ewingii: infects granulocytes
- presentation: same as anaplasmosis
- rash: often NOT even seen* - pinpoint maculopapular (“lacy”) rash
- systemic:
- prodrome - fever, chills
- thrombocytopenia
- elevated liver enzymes
- diagnosis: morulae - microbe within cytosplasmic vacules in phagocytic cells
- treatment: doxycycline

what are the two etiological agents for ehrlichiosis and how do they differ?
both obligate intracellular parasites carried by lone star tick
- erlichiae chaffeensis: infects monocytes - human form
- erlichiae ewingii: infects granulocytes
which form of erlichiosis invades humans?
erlichiae chaffeensis: infects monocytes - human form

morulae
cytplasmic inclusions of erlichiosis / amaplasmosis in a phagocyte
(in this case, anaplasma in a granulocyte)

morulae
cytplasmic inclusions of erlichiosis / amaplasmosis in a phagocyte
(in this case, erlichiosis in a monocyte)
anaplasmosis
- pathogenesis
- presentation
- diagnosis
- treatment
- pathogenesis: anaplasma phagocytophilum - an obligate intracellular pathogen - is transmitted via ixodes tick
- presentation: same as anaplasmosis
- rash: often NOT even seen* - pinpoint maculopapular (“lacy”) rash
- systemic:
- prodrome - fever, chills
- thrombocytopenia
- elevated liver enzymes
- diagnosis: morulae - microbe within cytosplasmic vacules in granulocytes
- treatment: doxycycline
rocky mountain spotted fever
- pathogenesis
- presentation
- diagnosis
- treatment
- pathogenesis: rickesttiae rickettsiae - a obligate intracellular pathogen transmitted by ixodid tick - infects vascular endothelial cells
- presentation:
- skin: ascending rash that starts from the wrists & ankles and the moves centripitally (outward -> inward) within hours. is
- non-pruritic
- involving the soles & palms
- systemic: significant involvement
- muscle degeneration
- edema - periorbital* & peripheral (pulmonary, cerebral)
- conjunctival suffusion*
- thrombocytopenia (like anaplasma, erclichiosis)
- skin: ascending rash that starts from the wrists & ankles and the moves centripitally (outward -> inward) within hours. is
- treatment: doxycyline
what presentations can rock mountain spotted fever have with respect to the eye?
- periorbital edema
- conjunctival suffusion
contrast the rashes caused by rickettsia (rocky mounted spotted fever & rickettsiapox) and erlichiosis / anaplasma ?
- RMSF (rickettsia, ixodids tick): ascending / centripital rash starting at wrists & ankles
- rickettialpox (rickettsia, mice): initial eschar + subsequent crop of vesiculopapules
- erlichiosis / anaplasma (lone star tick, ixodids tick): often undetectible, punctate rash
endemic typhus
- pathogenesis
- presentation
- diagnosis
- pathogenesis: infection via obligate intracellular pathogen by carried by lice from a flying squirrel vector
- presentation:
- systemic: prolonged high fever (104 F for ~2 weeks)
- rash: begins in axilla & trunk -> spreads centrifugally and out to extremities
- diagnosis: weil-felix test
flea-borne murine typhus
- pathogenesis
- demographics
- presentation
- pathogenesis: contraction of ricksettia typhi - an obligate intracellular coccobacillus - via fleas (from several animal reservoirs)
- demographics: contact with animals - cats, mice, opposum
- presentation:
- rash: begins on the trunk - spreads centrigually to extremities (like endemic typhus)
- systemic: classic prodrome
cutaneous tuberculosis
- pathogenesis
- presentation
- diagnosis
- pathogenesis. m tuberulosis (acid-fast aerobic bacillus) forms caseating (necrotic) granulomas
- can be triggered by BCG vaccination
- presentation: depends on if infection of primary or secondary:
- primary: enters skin via trauma sites
- no prior exposure to TB - > papule / nodule (“innoculation chancre”
- rrior exposure to TB -> warty lesions (“verrucosa cutis”)
- secondary: patient with TB In lung that dissseminates
-
tuburculoid granulomas
- red-brown
- painless
- on the head or the neck
-
tuburculoid granulomas
- primary: enters skin via trauma sites
- diagnosis:
- Mantoux test / IGRA test (no false + from vax)
- lesions beomes yellow-brown “apple jelly” upon application of pressure

leprosy / hansen’s disease
- pathogenesis
- presentation
- diagnosis
*
*
compare and contrast the etiological agents of
- cutaneous tuberulosis
- leprosy / hansen’s disease
- both are acid fast aerobic bacillus
- m. tuberulosis:
- NOT an obligate intracellular pathogen
- growth NOT restricted at 37 C
- m. leprae is
- obligate intracellulate
- growoth restricted at 37 C
- m. tuberulosis: