(Ch19) figurate Erythema Flashcards
Erythema annular Centrifugum (EAC) As/w
- Hypersensitivity
- Infections
- Drugs
- other disorders
- Paraneoplastic
- Pregnancy
infections As/w EAC
- Fungal/Dermatophyte:
-Tinea Pedis, Candida, Penicllium - Viruses: pox, EBV, VZV, HIV
- Bacteria: pseudomonas
- Parasite: phithirus pubis
Disorders As/w EAC
Crohn’s
AI-Endo
HES
Which figurate erythema can be triggered by pregnancy?
EAC
How fast does EAC lesion grows
> 6cm in 1-2w
Clinical characteristics of EAC rash?
annular expand centrifugally
with trialing scales in the inner ring
resolves with PIH and no scar
Common sites for EAC
Thighs and hips
Superficial vs Deep EAC
Superficial: trailing scales and pruritic
Deep: no scales , no pruritus but elevated edge
How to associate EAC with a disease clinically?
Flares correlate with disease recurrence
which Histopth findings correlates with trailing scales of EAC
Spongiosis +focal parakeratosis
characteristic sign of EAC in histopath?
Coat sleeves
PV aggregate of inflammation cells
Rx of EAC
Symptomatic:
Topical antipruritics & sedating Anti-H
Therapeutic:
* Rx underlying disease
* TCS to the advancing border
* SCS (can induce remission) However a/w↑recurrence after D/C
* Empiric antibiotics or antifungals (Macrolides)
at what age EAC increases ?
5th decade
Famillial variant AD
what malignancies as/w EAC
hematologic
leukemia/lymphoma
Drugs As/w EAC
Diuretics
NASIADs
Ustekinumab
Rituximab
Antimalaria
what percentage of acute RF develop Erythema Marginatum
10%
pathogenesis of Erythema Marginatum
Molecular mimicry/cross reactivity of Group A B-hemolytic strep antigens with Myosin,Actin, tropomyosin and keratin
Virulence factors for strep pyogenes
- M protein and mucoid colony –> Acute RF
- Cysteine proteases: exotoxin B and IgG degrading enzyme
which virulence factor of GAB strep As/w Cardiotoxicity
cysteine proteases
skin lesions As/w RF
- Erythema Marginatum (Asx)
- Subcutaneous nodules (painless)
Erythema Marginatum latency period after strep pharyngitis
2-5w
Erythema Marginatum clinical presentation
ASx Red macules spread peripherally into larger patches or plaques
NO scales
Erythema Marginatum migration speed
1-12mm over 12h
Which part of the body spared by Erythema Marginatum
Face
What factor can accentuate Erythema Marginatum rash
Heat
Erythema Marginatum As/w carditis and arthritis MC in?
kids <5y
younger the higher the risk
typical age of RF (5-15y)
prognosis of Erythema Marginatum
resolves spontaneously unrelated to acute RF course
Diagnostic criteria of RF
JONES criteria
evidence of preceding pharyngitis can be identified in jones criteria by?
+ve cx
or
elev ASO
or
elev anti-DNase B
Jones criteria diagnosis requirements
evidence of GA strep
+
2 major (JONES)
or
evidence of GA strep
+
1 major
+
2 minor
what percentage of untreated strep throat evolve into RF
3%
figurate erythema can present as paraneoplastic
EAC
Erythema gyratum repenes
Erythema Gyratum Repens pthogensis
Cross-reaction b/w tumor & cutaneous antigens
possibly glutamine metabolism within skin
Erythema Gyratum Repens clinical features
Have a wood-grain or zebra-like pattern▸ “rings w/in rings”
Multiple, annular or polycyclic, red lesions w/ peripheral scale +/= pruritus
MC malignancy As/w Erythema Gyratum Repens
- Lung
- Breast
- Esophagus
- Gastric
percentage of Erythema Gyratum Repens as/w Malignancies
70%
Conditions As/w Erythema Gyratum Repens
Neoplasms
pulmonary TB
Acquired ichthyosis
PPK
Hypereosinophilia
what condition when resolving can appear like Erythema Gyratum Repens
PRP
how rapidly does Erythema Gyratum Repens advance
1cm/day
percentage of Lyme with Erythema migrans
60-90%
What is the initial manifestation of Lyme
Erythema migrans
Organism causing Lyme and its type
Borrelia burgdorferi
a spirochete
Borrelia burgdorferi reservoir ?
White footed mice
White footed deer
Chipmunks
Birds
Tick/vector transimitting Borrelia burgdorferi
Ixodes deer ticks
How long does the tick needs to be attached to transmit Borrelia burgdorferi?
> 1 day
mostly >48h
Lyme percentages ?
EM 60-90%
Spirochetemia 45%
Multiple lesions 20 - 25%
on the lesion where can you find B. burgdorferi
centre and periphery of the lesion
List few co-infection with B. burgdorferi can be carried by Ixodes tick
Babesia microti (babesiosis)
Anaplasma phagocytophilum (Anaplasmosis)
Borrelia miyamotoi
when to consider co-infection in Lyme?
Prolonged/severe manifestation
Cytopenias
High fever
Which protein produced by tick to enhance transmission of B. burgdorferi?
tick salivary protein (Salp15)
tick salivary protein (Salp15) function?
- protection against antibody-mediated killing.
- inhibits adaptive immune responses
where does Salp15 binds in B. burgdorferi?
outer surface protein C
What size the primary lesion in Lyme must be ?
≥5 cm
Clinical appearance of Erythema migrans ?
Bull’s eye
Large annular red expanding patch
percentage of Lyme with multiple Erythema migrans and what is the proposed hypothesis?
(20 - 25%)
2/2 multiple tick bites
or
Spirochetemia (lymphatic/ hematologic spread)
appear days-wks after appearance of primary EM
When does Erythema migrans appear after tick bite ?
7–15 days after tick detachment (range 3-30 days).
Common locations for Erythema migrans
Trunk and intertriginous areas
Phases of Lyme disease ?
- Early localized disease
- Early disseminated disease
- Chronic disease
Timing of the year with increase Lyme and geographic location?
↑ spring and summer, (outdoors, woods)
US (Northeast, mid-Atlantic, and Great Lakes regions) and in northern and eastern Europe.
Early localized disease phase of Lyme presents with?
Flu like sx
lymphadenopathy
Early disseminated disease of Lyme presents with?
Bell’s palsy
Arthritis
AV block
Iritis
Which Lyme phases have Erythema migrans
- Early localized disease
- Early disseminated disease
Chronic disease phase of Lyme presents with?
- chronic arthritis (usually monoarticular of large joints
- Encephalopathy
- Acrodermatitis chronica atrophicans (chronic sclerosing dermatitis)
which phase of Lyme presents with cardiac sx
Early disseminated disease
what type of rash presents with chronic phase of Lyme
Acrodermatitis chronica atrophicans (chronic sclerosing dermatitis)
which phase of Lyme presents with meningitis/encephalopathy?
Chronic
definition of Confirmed Lyme requires ?
EM + exposure hx
or
EM + lab evidence (no exposure)
or
1 or more late manifestation + lab evidence
Probable Lyme definition requires ?
Physician opinion + lab
Suspected Lyme
EM + no lab + no hx
name of Agar for Borrelia
Barbour-Stoenner-Kelly medium
Lyme Rx
Doxycycline
Ampicillin: if pregnant or <8y
Ceftriaxone if:
-Cardiac
- Meningitis
- Persistent Arthritis
All for 14 days
prognosis of Lyme ?
Self resolves < 6 weeks (median 4 weeks).
- 60% arthritis (usually knee)
- 10% neurologic issues (usually Bell’s palsy)
- 5% cardiac issues (usually AV block
Diagnosis of Borrelia?
- PCR: skin bx or urine
- Culture in Agar
- Serology:
- ElISA confirmed by Western blot
- IgM
Prophylaxis for Lyme indications?
prophylaxis with Doxy for (must all be present) :
- Adult non pregnant
-Attached tick identified - Tick attached for >36h
-prophylaxis begain <72h of tick removal
When does Erythema Gyratum Repens appears in relation to neoplasms ?
Cutaneous lesions appear 1 year prior to 1 year after the development of the neoplasm
Name 3 stains for spirochetes?
Warthin-Starry silver stain
Dieterle
Steiner
