INTRODUCTION:

Erythema migrans or erythema chronicum migrans is an expanding rash often seen in the early stage of Lyme disease, and can also (but less commonly) be caused by southern tick-associated rash illness (STARI)^4,5. It can appear anywhere from one day to one month after a tick bite. This rash 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 for "migrating redness".

Approximately 70% to 80% of people with Lyme disease, which is spread by ticks, will develop erythema migrans. It will usually show up at the site of a tick bite within 3 to 30 days after being bitten. It will gradually expand, although it doesn't always appear the same on everyone.¹

Definition:

Erythema migrans is a rash that frequently appears as one of the first symptoms of Lyme disease. It's typically a circular red area that sometimes clears in the middle, forming a bull's-eye pattern. It can spread up to 12 inches across and may be warm to the touch.

Clinical Manifestation:

Erythema migrans is a large rash, usually measuring about 2 to 2.5 inches and expanding gradually. It can reach up to 12 inches or more. The rash appears where you were bitten by a tick somewhere between 3 and 30 daysTrusted Source after the bite. For most people, it will appear within 7 to 10 days.

Many people notice a bump or redness immediately after a tick bite, but this usually goes away in a few days and is not a sign of Lyme disease. An erythema migrans rash may feel warm when you touch it, but it’s rarely painful or itchy. Because the rash is an early sign of Lyme disease, you might also experience:

Fever, headache, chills, joint aches, swollen lymph nodes

Once the rash appears, it will begin to expand and can reach over six inches wide. In some people, the rash can start to clear as it gets bigger, causing the bull’s-eye rash many people associate with Lyme disease. However, solid, circular rashes are the most common type in the United States. Some people with darker complexions might have a rash that looks like a bruise.²

Pathophysiology:

Erythema migrans occurs relatively early in infection after an infected tick has fed

transmitted the bacterium, and dropped off. The rash results from a person’s adaptive immune response: infiltration of lymphocytes, plasma cells, and other types of cells.

The Erythema Migrans is a transitional point in the infection.

With the evolution of the host immune response, the erythema migrans will spontaneously resolve, but spirochetes persist in the same tissue, without eliciting inflammation.

Thus, one of the earliest clinical signs of Lyme disease, erythema migrans, signals the onset of the immune phase of persistent infection, when spirochetes are sequestered in collagen with minimal or no inflammation.³

Risk Factor:

Ecological risk factors for both tick bites and erythema migrans were the proportion of the area covered by woods, sandy soil, dry uncultivated land, the number of tourist-nights per inhabitant and sheep population density. The cattle population density was a risk factor for erythem migrans.

The most common risk factors for Lyme disease include: Spending time in wooded or grassy areas. In the United States, deer ticks are found mostly in the heavily wooded areas of the Northeast and Midwest. Children who spend a lot of time outdoors in these regions are especially at risk⁴.

Cause:

Erythema migrans is not a reaction to a tick bite, but rather an outward sign of an actual Lyme disease infection in your skin. When the rash first appears, Lyme disease has likely just started to spread through your body, but is still more localized.

Erythema migrans is only caused by Lyme disease. A similar-looking circular rash is caused by a bite from a lone star tick, which is different from the tick that causes Lyme disease. But this rash will never be in the shape of a bull’s-eye.^5,6

Diagnosis:

A doctor can diagnose you with Lyme disease if you have erythema migrans and think you might have been bitten by a tick recently or were in a place where a tick bite could have occurred. It’s the only symptom that doctors can use to diagnose Lyme disease without blood tests.

While there are other rashes that look like erythema migrans, this rash is the only one of similar-looking rashes that will expand quickly and for many days after it appears. It’s also the only one that could appear as a bull’s-eye rash.

Even if a doctor diagnoses you with Lyme disease based on erythema migrans, they will do a blood test to confirm the diagnosis. An enzyme-linked immune sorbent assay (ELISA) detects antibodies to the bacteria that cause Lyme disease. It’s the most commonly used test.⁷

Investigation:

Even if a doctor diagnoses you with Lyme disease based on erythema migrans, they will do a blood test to confirm the diagnosis. An enzyme-linked immunosorbent assay (ELISA) detects antibodies to the bacteria that cause Lyme disease. It's the most commonly used test.

An enzyme immunoassay is used as a screening test to detect IgM and/or IgG antibodies in serum that are directed against the bacterium that causes LYME DISEASE.⁸

Treatment:

Lyme disease is treated with oral antibiotics, such as doxycycline (Acticlate, Doryx, Vibra-Tabs) or amoxicillin. A 14- to 21-day course of treatment will effectively treat the disease in most people. If your Lyme disease is in a later stage with neurological symptoms, you might need intravenous (IV) antibiotics.

Because an erythema migrans rash is a Lyme disease infection in the skin, any treatment for Lyme disease will also treat erythema migrans. If the rash is itchy or uncomfortable, you can try using an antihistamine to relieve itching or a cold compress to cool the rash area. However, you should ask your doctor before taking any medication for the rash specifically.⁹

COMPLICATION:

If left untreated, the infection sometimes extends or progresses over a period of months or years, leading to potentially severe neurological, articular, cutaneous and cardiac complications. How is erythema migrans associated with Lyme disease recognised and managed ¹⁰

Untreated Lyme disease can cause: Chronic joint inflammation (Lyme arthritis), particularly of the knee. Neurological symptoms, such as facial palsy and neuropathy. Cognitive defects, such as impaired memory.(https://www.mayoclinic.org)

DIAGNOSIS:

The differential diagnosis includes bacterial cellulitis, contact dermatitis, arthropod bite, herpes simplex or varicella zoster infection if the lesion is vesicular, tinea infection, urticaria, fixed drug eruption and a spider bite.

The first sign of erythema migrans is redness at the site of a tick bite. It will start to expand into a round or oval red skin lesion.

PROGONOSIS:

People treated with appropriate antibiotics in the early stages of Lyme disease usually recover rapidly and completely. Early diagnosis and proper antibiotic treatment of Lyme disease can help prevent late Lyme disease.

The prognosis for patients with Lyme disease is generally excellent when they are treated early with appropriate antibiotic regimens. However, recurrent infection is possible if the patient is again bitten by an infected tick; these infections are usually due to a different strain of the local Borrelia

REFERENCES:

1. https://www.webmd.com/skin-problems-and-treatments/what-to-know-erythema-migrans.

2. https://www.healthline.com/health/erythema-migrans.

3. (https://www.ncbi.nlm.nih.gov/books/NBK57011/)

4. https://pubmed.ncbi.nlm.nih.gov/9169184/#:~:text=Ecological% 20risk%20factors%20for%20both,risk%20factor%20for%20erythema%20migrans.

5. (https://www.healthline.com/health/erythema-migrans)

6. https://www.webmd.com/skin-problems-and-treatments/what-to-know-erythema-migrans.

7. (https://www.healthline.com/health/erythema-migrans

8. (https://www.google.com/search?q=investigation+for+erythemia+migrains&rlz=1C1GNAM_enGBIN688IN688&oq=investigation+for+erythemia+migrains&aqs=chrome..69i57j33i10i22i29i30.55852j0j15&sourceid=chrome&ie=UTF-8)

9. (https://pubmed.ncbi.nlm.nih.gov/26594731/)

Received on 20.03.2022 Modified on 23.04.2022

Int. J. Nur. Edu. and Research. 2022; 10(3):273-275.

DOI: 10.52711/2454-2660.2022.00064