7 - 46 - ERYTHEMA ANNULARE CENTRIFUGUM AND OTHER FIGURATE ERYTHEMAS Flashcards
variants of EAC
*** superficial variant: **lesions are slightly elevated and demonstrate desquamation at the inner margin, also referred to as a “trailing scale”
* deep variant: has an indurated, firm border, often without prominent scaling
most common symptom associated with EAC
pruritus
most frequent sites of involvement of EAC
buttocks, thighs, and trunk
characteristic scale of EAC
desquamation at the inner margin, also referred to as a “trailing scale”
risk factors for EAC
infections, malignancies, medications, pregnancy, and other systemic diseases
- In one study, 40% of patients with EAC had a concomitant superficial dermatophyte infection, most commonly tinea pedis, and 13% had internal malignancies, including non-Hodgkin lymphoma and acute myelogenous leukemia
this infection may be a risk factor for EAC.
Dermatophyte infections
- In cases associated with tinea pedis, lesions of EAC tend to resolve with treatment of the dermatophytosis
- In addition to dermatophytoses, EAC is associated with other cutaneous infections such as molluscum contagiosum and herpes zoster, as well as systemic infections, including Epstein-Barr virus and HIV.
histopath finding of EAC
- dense perivascular infiltrate composed of lymphocytes, histiocytes, and occasional eosinophils that tightly wraps around blood vessels described as “coat-sleeve” pattern
Cutaneous manifestation of early localized Lyme disease that occurs at the site of the bite of Ixodes species ticks
ERYTHEMA MIGRANS
insect vector of Lyme disease
Ixodes scapularis tick
bacteria causing Lyme disease
Borrelia burgdorferi
annular erythema that expands to create a “bull’s-eye” appearance
ERYTHEMA MIGRANS
3 stages of Lyme disease
**1. early localized disease: **characterized by erythema migrans
2. early disseminated disease: if untreated, patients can progress to the second stage of Lyme disease, which involves widespread spirochete dissemination with neurologic, rheumatologic, and cardiac involvement
3. chronic disease:persistent neuroborreliosis, severe erosive arthritis, and acrodermatitis chronica atrophicans
hallmark cutaneous finding of the first stage of Lyme disease
Erythema migrans occurs at the initial site of the tick bite
- It is characterized by an erythematous expanding annular plaque with a central area of clearing, often described as a “bull’s-eye” lesion
- Lesions grow centrifugally and can grow at a rate of up to **3 cm per day. **
- At the time of presentation, the mean diameter of lesions of erythema migrans are 10 to 16 cm, depending on the site of involvement, with larger lesions found on the trunk and smaller lesions found on the lower extremities.
- Multiple lesions of erythema migrans can be seen in the setting of multiple tick bites or spirochetemia or lymphatic spread
most common associated symptoms of erythema migrans
**warmth, pruritus, and pain, **although it can be asymptomatic
- In some cases, erythema migrans can be vesicular.
Primary lesions of erythema migrans occur in areas where tick bites are likely to occur and go unnoticed, such as what areas?
trunk, axillae, groin, and popliteal fossae
In most cases, ticks must be attached for at least how many hours before bacteria is transmitted?
24 hours
erythema migrans occurs at the site of the bite approximately how many days after tick detachment?
7 to 14 days after tick detachment (range: 3 to 30 days)
- Approximately 70% to 80% of individuals infected with Lyme disease develop lesions of erythema migrans, and up to 45% of patients presenting with erythema migrans have spirochetemia
Acrodermatitis chronica atrophicans is typical at what stage of Lyme disease
Chronic Lyme disease
characterized by enlarging, edematous plaques on the distal extremities with a bluish-red hue that evolve into atrophic plaques
Acrodermatitis chronica atrophicans
benign reactive lymphoid hyperplasia that can occur in response to untreated Borrelia infections
Borrelial lymphocytoma
Borrelial lymphocytoma is usually observed in what stage of lyme disease?
early disseminated
more associated with Borrelia afzelii and Borrelia garinii
most common antibiotics used to treat Lyme disease
doxycycline, amoxicillin, and cefuroxime
Prophylaxis with a single dose of what antibiotic is indicated to decrease the risk of developing Lyme disease?
doxycycline
doxycycline prophylaxis can be started within how many hours of tick removal?
72 hours
Prophylaxis with a single dose of doxycycline is indicated to decrease the risk of developing Lyme disease only when the individual is from an endemic area, has been bitten by a tick identified as I. scapularis, has had tick attachment for longer than 36 hours, and prophylaxis can be started within 72 hours of tick removal.
doxycycline prophylaxis is indicated if the tick attachment is longer than how many hours?
36 hours
Prophylaxis with a single dose of doxycycline is indicated to decrease the risk of developing Lyme disease only when the individual is from an endemic area, has been bitten by a tick identified as I. scapularis, has had tick attachment for longer than 36 hours, and prophylaxis can be started within 72 hours of tick removal.
Cutaneous manifestation of rheumatic fever, occurring after pharyngeal infection with group A β-hemolytic streptococcus.
ERYTHEMA MARGINATUM
- classically presents as erythematous macules that spread to become annular or polycyclic patches or plaques.
- As the lesions expand centrifugally, there can be a central area of clearing.
- The borders of the lesions are often well demarcated.
- There are usually no epidermal changes present and the lesions are often asymptomatic.
- Individual lesions tend to appear and disappear, and** may be more evident with hot showers or baths.**
diagnostic criteria of rheumatic fever
Major Criteria:
1. Carditis
2. Migratory polyarthritis
3. Sydenham chorea
4. Subcutaneous nodules
5. Erythema Marginatum
Minor Criteria
1. fever
2. arthralgias
3. abnormal laboratory findings such as elevated ESR, CRP, or a prolonged PR interval on echocardiogram
Required for diagnosis: 2 major or 1 major and 2 minor criteria
(2-0-1-2)
One of the major criteria of acute rheumatic fever.
ERYTHEMA MARGINATUM
- Only seen in a minority of patients with acute rheumatic fever
- seen in fewer than 10% of patients with acute rheumatic fever.
- It occurs more often in children than in adults, with peak age of onset between 5 and 15 years
Acute rheumatic fever occurs as a complication of what infection secondary to what bacteria?
antecedent pharyngeal infection with group A β-hemolytic streptococcus
areas of predilection of erythema marginatum
trunk, axillae, and proximal extremities, and typically spare the face
Individual lesions tend to appear and disappear, and** may be more evident with hot showers or baths.**
Erythema marginatum
less-common complication associated with acute rheumatic fever which is a chronic, painless arthropathy of the hands and feet.
Jaccoud arthropathy
Usually a paraneoplastic phenomenon
ERYTHEMA GYRATUM REPENS
Characteristic wood grain appearance with multiple concentric rings.
ERYTHEMA GYRATUM REPENS
- The epidermis often has a superficial scale at the edges, and patients often complain of pruritus.
- The onset of the lesions can occur from 1 year before to 1 year after the diagnosis of malignancy.
- Additional associated cutaneous findings can be seen, which include acquired ichthyosis and palmoplantar keratoderma
Thought to be an immune reaction caused by cross-reaction between tumor and skin antigens.
ERYTHEMA GYRATUM REPENS
most common cancers associated with Erythema gyratum repens
lung, breast, esophagus, and stomach neoplasms
Erythema gyratum repens features multiple, erythematous, annular lesions that advance at a rapid rate of up to how many cm per day?
1 cm
erythema annular centrifugum (EAC)
Erythema migrans
Erythema marginatum (also, erythema marginatum rheumaticum)
Erythema gyratum repens
