Erythema migrans or erythema chronicum migrans is an expanding
rash
A rash is a change of the human skin which affects its color, appearance, or texture.
A rash may be localized in one part of the body, or affect all the skin. Rashes may cause the skin to change color, itch, become warm, bumpy, chapped, dry, c ...
often seen in the early stage of
Lyme disease
Lyme disease, also known as Lyme borreliosis, is a vector-borne disease caused by the '' Borrelia'' bacterium, which is spread by ticks in the genus '' Ixodes''. The most common sign of infection is an expanding red rash, known as erythema ...
, and can also (but less commonly) be caused by
southern tick-associated rash illness (STARI).
[ Page last reviewed: October 22, 2015] It can appear anywhere from one day to one month after a
tick bite
Ticks (order Ixodida) are parasitic arachnids that are part of the mite superorder Parasitiformes. Adult ticks are approximately 3 to 5 mm in length depending on age, sex, species, and "fullness". Ticks are external parasites, living b ...
. This
rash
A rash is a change of the human skin which affects its color, appearance, or texture.
A rash may be localized in one part of the body, or affect all the skin. Rashes may cause the skin to change color, itch, become warm, bumpy, chapped, dry, c ...
does not represent an allergic reaction to the bite, but rather an actual skin infection of one of the Lyme bacteria species
from the genus ''Borrelia''. The rash's name comes from
New Latin
New Latin (also called Neo-Latin or Modern Latin) is the revival of Literary Latin used in original, scholarly, and scientific works since about 1500. Modern scholarly and technical nomenclature, such as in zoological and botanical taxonomy ...
for "migrating redness".
Lyme disease
"Erythema migrans is the only manifestation of Lyme disease in the United States that is sufficiently distinctive to allow clinical diagnosis in the absence of laboratory confirmation." Often, but not always, mentions of a
target lesion (bull's-eye lesion) are talking about erythema migrans. However, the appearance of erythema migrans can vary considerably: while some look like a bull's eye, in the U.S. most are evenly red or bluish, without a central or ring-like clearing.
A minority of patients never have any rash. Because Lyme disease can within a few weeks cause long-term neurologic complications, persons with a rash and recent history of outdoor activities where Lyme is common should seek a doctor for diagnosis.
Presentation
The initial sign of about 80% of Lyme infections is an erythema migrans (EM) rash
A rash is a change of the human skin which affects its color, appearance, or texture.
A rash may be localized in one part of the body, or affect all the skin. Rashes may cause the skin to change color, itch, become warm, bumpy, chapped, dry, c ...
at the site of a tick bite, often near skin folds, such as the armpit
The axilla (also, armpit, underarm or oxter) is the area on the human body directly under the shoulder joint. It includes the axillary space, an anatomical space within the shoulder girdle between the arm and the thoracic cage, bounded superior ...
, groin
In human anatomy, the groin (the adjective is ''inguinal'', as in inguinal canal) is the junctional area (also known as the inguinal region) between the abdomen and the thigh on either side of the pubic bone. This is also known as the medial comp ...
, or back of knee, on the trunk
Trunk may refer to:
Biology
* Trunk (anatomy), synonym for torso
* Trunk (botany), a tree's central superstructure
* Trunk of corpus callosum, in neuroanatomy
* Elephant trunk, the proboscis of an elephant
Computing
* Trunk (software), in rev ...
, under clothing straps, or in children's hair, ear, or neck.[ Most people who get infected do not remember seeing a tick or the bite. The EM rash appears typically one or two weeks (range 3–32 days) after the bite. The most distinctive features of the EM rash are the speed and extent to which it expands, respectively 2–3 cm per day and up to a diameter of 5–70 cm (50% attain more than 16 cm).][ The rash is usually circular or oval, red or bluish, and may have an elevated or darker center.][ In about 79% of cases in Europe but only 19% of cases in endemic areas of the U.S., the rash gradually clears from the center toward the edges, possibly forming a "bull's eye" pattern.][ The rash may feel warm but usually is not itchy, is rarely tender or painful, and takes up to four weeks to resolve if untreated.]
The EM rash is often accompanied by symptoms of a viral-like illness, including fatigue, headache, body aches, fever, and chills, but usually not nausea or upper-respiratory problems. These symptoms may also appear without a rash, or linger after the rash disappears. Lyme can progress to later stages without these symptoms or a rash.[
A person with an asymptomatic EM rash can easily miss its significance. However, if the initial EM rash is not treated, the infection can disseminate through the lymphatic system or blood. Within days or weeks, additional EM rashes, usually smaller, can appear at other sites, or the infection can cause more serious complications in the nervous system, heart, or joints.][
]
Southern tick-associated rash illness
Southern tick-associated rash illness (STARI) produces a similar rash pattern although it develops more quickly and is smaller. This erythema
Erythema (from the Greek , meaning red) is redness of the skin or mucous membranes, caused by hyperemia (increased blood flow) in superficial capillaries. It occurs with any skin injury, infection, or inflammation. Examples of erythema not asso ...
is also sometimes called erythema migrans or EM. The associated infectious agent has not been determined. Antibiotic treatment resolves the illness quickly.
Treatment
Both Lyme disease and STARI can be treated with antibiotics
An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and preventio ...
, particularly doxycycline
Doxycycline is a broad-spectrum tetracycline class antibiotic used in the treatment of infections caused by bacteria and certain parasites. It is used to treat bacterial pneumonia, acne, chlamydia infections, Lyme disease, cholera, typhus ...
.
History
In a 1909 meeting of the Swedish Society of Dermatology, Arvid Afzelius
Arvid Afzelius (1857–1923) was a Swedish dermatologist.
As a student at the Karolinska institutet, Afzelius studied under the prominent dermatologist Moritz Kaposi (1837–1902) in Vienna. Kaposi has now become a household name because "his" ...
first presented research about an expanding, ring-like lesion he had observed. Afzelius published his work 12 years later and speculated the rash came from the bite of an ''Ixodes
''Ixodes'' is a genus of hard-bodied ticks (family Ixodidae). It includes important disease vectors of animals and humans ( tick-borne disease), and some species (notably '' Ixodes holocyclus'') inject toxins that can cause paralysis. Som ...
'' tick
Ticks (order Ixodida) are parasitic arachnids that are part of the mite superorder Parasitiformes. Adult ticks are approximately 3 to 5 mm in length depending on age, sex, species, and "fullness". Ticks are external parasites, living ...
, meningitic symptoms and signs in a number of cases and that both sexes were affected. This rash was known as erythema chronicum migrans, the skin rash found in early-stage Lyme disease.
In the 1920s, French physicians Garin and Bujadoux described a patient with meningoencephalitis, painful sensory radiculitis, and erythema migrans following a tick bite, and they postulated the symptoms were due to a spirochetal infection. In the 1940s, German neurologist Alfred Bannwarth
Alfred Bannwarth (1903–1969) was a German neurologist who is credited for first reporting lymphocytic meningoradiculitis.
Biography
Early life and education
After first studying music, Bannwarth studied medicine in Munich, Germany, and ...
described several cases of chronic lymphocytic meningitis and polyradiculoneuritis, some of which were accompanied by erythematous
Erythema (from the Greek , meaning red) is redness of the skin or mucous membranes, caused by hyperemia (increased blood flow) in superficial capillaries. It occurs with any skin injury, infection, or inflammation. Examples of erythema not asso ...
skin lesions.
References
External links
*
{{Urticaria and erythema
Bacterium-related cutaneous conditions
Lyme disease
Spirochaetes
de:Lyme-Borreliose#1. Stadium: Lokalinfektion