Figurate Erythema

Question 1

Clinical presentation of erythema annular centrifugum?

Answer 1

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

Question 2

Epidemiology of erythema annular centrifugum?

Answer 2

Usually presents in the 5th decade. It is a reactive process a/w tinea pedis and other triggers

Question 3

What is the key difference between erythema annular centrifugum and urticaria?

Answer 3

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.

Question 4

Causes of EAC?

Answer 4

Dermatophyte (like an id rxn), infection (like rickettsia), neoplasms, pregnancy, virus, lupus, graves, drugs, think of it as a reactive immune cause, blue cheese

Question 5

What is erythema marginatum?

Answer 5

Cutaneous manifestation of rheumatic fever, it is one of the criteria for the dx scarlet fever.

Question 6

Epidemiology of erythema marginatum?

Answer 6

Mostly occurs in children

Question 7

Presentation of erythema marginatum?

Answer 7

Asymptomatic migratory annular and polycyclic erythematous eruption. It has subQ nodules but no epidermal changes.

Question 8

Presentation of erythema migrans?

Answer 8

Caused by Borrelia spp. rash presents 2-28 days after tick bite, usualy asymptomatic, rash spontaneously resolves within 6 weeks

Question 9

What are the hosts for the borrelia spp?

Answer 9

White-tailed deer, mice harbor the spirochete, ticks pick it up from this (these animals are reservoirs)The tick is the vector

Question 10

What percentage of Lyme disease pts have the initial rash?

Answer 10

60-90%

Question 11

What do you suspect when the rash becomes generalized?

Answer 11

They can have disseminated disease, via lymphatic spread

Question 12

How long does the tick need to be attached to pass Lyme?

Answer 12

At least 24 hrs

Question 13

What is the chronic Lyme disease cutaneous finding?

Answer 13

Acrodermatitis chronica atrophicans, this is only in those in Europe as the North American borrelia species does not cause this.

Question 14

What is the species of Borrelia in the European form of Lyme disease?

Answer 14

Borrelia afzelii (vs. Borrelia burgdorferi in the US)

Question 15

Clincal presentation of erythema gyratum repens?

Answer 15

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.

Question 16

How fast do the erythema gyratum repens lesions migrate?

Answer 16

They can migrate up to 1 cm/day

Question 17

What is EGR a/w

Answer 17

Strongly a/w underlying malignancy, esophageal/GI cancer in Asian patients

Question 18

If the rash of EGR recurs what must be considered?

Answer 18

Look for recurrence or metastasis.

Question 19

What is the most commonly affected area in erythema annulare centrifugum?

Answer 19

The inner thighs/hips, but can also become more generalized

Question 20

How fast do the lesions expand in erythema annulare centrifugum?

Answer 20

Up to 6cm in diameter in 2 weeks

Question 21

What is the difference in speed of expansion in erythema annulare centrifugum and erythema gyratum repens?

Answer 21

The spread of the erythema in erythema gyratum repens is much faster (1cm/day)

Question 22

What is the histology of erythema annulare centrifugam?

Answer 22

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

Question 23

Treatment for EAC?

Answer 23

Remove the underlying trigger or topical steroids

Question 24

What is the timing and presentation of rheumatic fever after a GAS infxn?

Answer 24

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

Question 25

What is the clinical presentation of erythema marginatum?

Answer 25

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

Question 26

What is the progression of erythema marginatum?

Answer 26

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

Question 27

What is needed for the dx of Lyme’s dz?

Answer 27

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)

Question 28

How long into the infection does it take to see the peak IgM response to Borrelia?

Answer 28

3-6 weeks

Question 29

Treatment for Lyme disease?

Answer 29

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

Question 30

What is the prognosis of Lyme dz is left untreated?

Answer 30

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)

Question 31

What are the most common underlying cancers in erythema gyratum repens?

Answer 31

Lung (most common) >breast and GI (esophagus/stomach)