Figurate Erythema Flashcards
Clinical presentation of erythema annular centrifugum?
2 forms: superficial (favor thighs - trialing scale) and deep form (favor trunk, no scale). Lesions last for weeks to a month, p/w annular, arciform, polycyclic plaques w/ infiltrated border and central clearing
Epidemiology of erythema annular centrifugum?
Usually presents in the 5th decade. It is a reactive process a/w tinea pedis and other triggers
What is the key difference between erythema annular centrifugum and urticaria?
The scale! Remember though that the deep one on the trunk doesn’t have to have scale. Also, pay attention to the leading edge as urticaria usually shouldn’t expand.
Causes of EAC?
Dermatophyte (like an id rxn), infection (like rickettsia), neoplasms, pregnancy, virus, lupus, graves, drugs, think of it as a reactive immune cause, blue cheese
What is erythema marginatum?
Cutaneous manifestation of rheumatic fever, it is one of the criteria for the dx scarlet fever.
Epidemiology of erythema marginatum?
Mostly occurs in children
Presentation of erythema marginatum?
Asymptomatic migratory annular and polycyclic erythematous eruption. It has subQ nodules but no epidermal changes.
Presentation of erythema migrans?
Caused by Borrelia spp. rash presents 2-28 days after tick bite, usualy asymptomatic, rash spontaneously resolves within 6 weeks
What are the hosts for the borrelia spp?
White-tailed deer, mice harbor the spirochete, ticks pick it up from this (these animals are reservoirs)The tick is the vector
What percentage of Lyme disease pts have the initial rash?
60-90%
What do you suspect when the rash becomes generalized?
They can have disseminated disease, via lymphatic spread
How long does the tick need to be attached to pass Lyme?
At least 24 hrs
What is the chronic Lyme disease cutaneous finding?
Acrodermatitis chronica atrophicans, this is only in those in Europe as the North American borrelia species does not cause this.
What is the species of Borrelia in the European form of Lyme disease?
Borrelia afzelii (vs. Borrelia burgdorferi in the US)
Clincal presentation of erythema gyratum repens?
Migratory figurate erythema with multiple concentric rings that looks like a grain of wood. There are central areas of clearing and an outer border and inner border.
How fast do the erythema gyratum repens lesions migrate?
They can migrate up to 1 cm/day
What is EGR a/w
Strongly a/w underlying malignancy, esophageal/GI cancer in Asian patients
If the rash of EGR recurs what must be considered?
Look for recurrence or metastasis.
What is the most commonly affected area in erythema annulare centrifugum?
The inner thighs/hips, but can also become more generalized
How fast do the lesions expand in erythema annulare centrifugum?
Up to 6cm in diameter in 2 weeks
What is the difference in speed of expansion in erythema annulare centrifugum and erythema gyratum repens?
The spread of the erythema in erythema gyratum repens is much faster (1cm/day)
What is the histology of erythema annulare centrifugam?
Superficial EAC: mild spongiosis, focal parakeratosis in mounds, perivascular lymphohistiocytic infiltration which is tight and dense, often called “coat sleeving”
Deep EAC: You see the coat-sleeving with the perivascular lymphohistiocytic inflammation but it is deeper
Treatment for EAC?
Remove the underlying trigger or topical steroids
What is the timing and presentation of rheumatic fever after a GAS infxn?
Represents an aberrant humoral/cellular response to the bacteria. Starts 2-5 weeks after the infxn
Jones major criteria: carditis migratory polyarthritis, erythema marginatum, subcutaneous nodules, or Sydenham’s chorea
Also look for fever, arthralgias, or abnormal lab findings like elevated ESR, CRP and PR interval
What is the clinical presentation of erythema marginatum?
Migratory expanding annular/polycyclic patches/plaques starting as macules. These usually involve the trunk, axillae, and proximal extremities
can migrate 2-12 mm in a half day
What is the progression of erythema marginatum?
Usually resolves in a few weeks and is seen in the active phase of rheumatic fever
No treatment has been shown to alter the course of the condition
What is needed for the dx of Lyme’s dz?
Erythema migrans + either known exposure or laboratory evidence of exposure (+ tissue/fluid culture, tissue/fluid PCR, and anti-Borrelia antibodies via ELISA and Wester blot)
How long into the infection does it take to see the peak IgM response to Borrelia?
3-6 weeks
Treatment for Lyme disease?
Doxycycline in early localized disease and mild early disseminated or chronic disease for those that are not pregnant or are >8 yrs old
In those that are pregnant or children <8 use amoxicillin
Ceftriaxone IV for Lyme meningitis/severe dz
What is the prognosis of Lyme dz is left untreated?
Lesions on the skin will self-resolve in 6 weeks
60% will develop arthritis (usually in the knee), 10% will develop neurologic issues (usually Bell’s palsy), 5% will develop cardiac issues (AV block)
What are the most common underlying cancers in erythema gyratum repens?
Lung (most common) >breast and GI (esophagus/stomach)