Lyme Disease Mimics Cellulitis Skin Infection
Lyme disease can sometimes mimic cellulitis, a common bacterial skin infection. In this case, a 40-year-old woman developed redness, swelling, pain, and a rash at the site of a surgical excision.
The patient was initially treated with cephalexin and later switched to trimethoprim/sulfamethoxazole (TMP/SMX).
“Over the next 24 hours, there was a rapid expansion of abdominal redness and patchy areas of redness on her left groin and her right forearm,” the authors wrote.
The patient also complained of muscle and joint stiffness but attributed these symptoms to recent outdoor camping and exercise.
The woman was admitted for presumed postoperative cellulitis remote from surgery. Because of her recent camping trip and possible tick exposure, physicians prescribed doxycycline for suspected Lyme disease.
Within hours of starting doxycycline, the patient’s abdominal rash significantly receded, the forearm and leg rashes resolved, and the joint pain and stiffness improved markedly.
The Lyme disease diagnosis was confirmed with an IgM Western blot test.
“Initial suppression of the worsening rash could have been due to a low level of TMP/SMX activity on Borrelia burgdorferi stationary phase cells,” the authors explained.
[bctt tweet=”Rashes caused by Lyme disease may be incorrectly identified and attributed to other conditions such as cellulitis.” username=”DrDanielCameron”]
The patient’s IgG Western blot test was negative.
Lyme Disease Rashes Can Be Misidentified
Although Lyme disease can present with erythema migrans (EM) rashes, early rashes may be confused with cellulitis.
The authors suggested that “Lyme disease should be considered in patients with cellulitis in areas where Lyme disease is endemic.”
Lyme disease rashes have also been misidentified in other studies. In a case series involving 88 patients with erythema migrans, 13 had rashes that were initially misdiagnosed or treated incorrectly.
“Rashes were often misidentified by clinicians and patients as a spider bite, cellulitis, or shingles,” wrote Aucott and colleagues. [2]
The authors concluded that until more accurate tests are available for early Lyme disease, patients without a classic EM rash must be evaluated carefully.
In patients with skin lesions where cellulitis is uncertain, empiric antibiotics should be chosen that cover both Lyme disease and common bacterial causes of cellulitis.
Clinical Insight
Editor’s note: In my practice, I sometimes prescribe cefuroxime or amoxicillin/clavulanic acid if Lyme disease is a consideration. Neither cephalexin nor TMP/SMX are effective against Lyme disease.
If Lyme disease is suspected, I typically treat longer than 7–10 days.
You can view the rash in the open-access journal article.
Dr. Daniel Cameron, MD, MPH
Lyme disease clinician with over 30 years of experience and past president of ILADS.
Symptoms • Testing • Coinfections • Recovery • Pediatric • Prevention
This is very interesting, I too had a bite and went to the doctor they said it was shingles or cellulitis, both medications for these did not clear the issue, I went to ER because of concern of cellulitis not clearing up and the ER did see a red circle area and referred me to a dermatologist, she too saw the red circle area and I had been to Traverse City MI for a family vacation and it is a hot spot for Lyme, I had to beg her to keep me on doxycycline for two months, it cleared up the redness, but the pain and shooting pain my my leg continued for awhile but two plus years later I still suffer from swelling in my leg and ankle on the side I was bitten, horrible brain fog. I had the flu like symptom about 5 days later coming back from my trip and then right after that the redness on the back of my leg, horrible debilitating fatigue/exhaustion and other symptoms followed, got tested it came back negative but I know it was Lyme , I had all the symptoms and they treat you like you are making it all up and it is not uncommon for tests to come back negative. I am confused why I would make something up like this, I still get random deep nerve pain in the area that I was bitten. I live in AZ and no one here really is familiar with lyme disease. Luckily where I work my boss knew of a friend who had lyme so he was sympathetic to my issues. Terrified of Covid and just as terrified as getting a vaccine when I obviously have some active issues ongoing.
I had a terrible case of cellulitis in my wrist, for several months. , Antibiotics and steroids helped ease the pain some but for the most part I suffered. I had the heat, swelling shoot pain and stabbing pain. I was helpless.
Seven months out my fingers on that hand stay swollen and I am unable to use my hand and still have some pain in my wrist. Last month I was diagnosed with Lyme disease. Prior to all this I worked 10 hour days using impact tool building box truck bodies. I’m a sixty year old female. I haven’t work in almost a year because of this. I have pain in my shoulders my back and neck. I’m trying to fight this. No more funds to go back to doctor. Trying herbs for what that’s worth…