Can Acrodermatitis Chronica Atrophicans Occur in the United States?
Acrodermatitis chronica atrophicans is a late skin manifestation of Lyme disease
It has traditionally been associated primarily with European Lyme disease
A 2026 U.S. case series challenges the assumption that European travel is always necessary
Can acrodermatitis chronica atrophicans occur in the United States? Yes, although it appears to be extremely rare. A 2026 case series described three U.S. patients with acrodermatitis chronica atrophicans (ACA), including one Pennsylvania woman who had never traveled outside the United States.1
ACA is a chronic skin manifestation of Lyme borreliosis that is well recognized in Europe but rarely reported in the United States. It typically begins with slowly progressive reddish, bluish, or violaceous discoloration and swelling, often involving the hands, feet, arms, or legs. Over time, the affected skin can become thin, atrophic, or sclerotic.1,2
The new cases are clinically interesting because ACA has traditionally been associated primarily with Borrelia afzelii, a European Borrelia species not considered endemic in the United States. The report raises an important question: can an ACA-like manifestation occasionally develop after Lyme disease acquired in the United States?
What Is Acrodermatitis Chronica Atrophicans?
Acrodermatitis chronica atrophicans is considered a late cutaneous manifestation of Lyme borreliosis. Unlike the more familiar skin manifestations of Lyme disease, such as erythema migrans, ACA may develop months or years after the initial infection and can persist if untreated.1,2
The condition usually affects the extremities. Early findings may include swelling and reddish-blue or violaceous discoloration. As the process progresses, the skin can become increasingly thin or hardened. Some patients also develop pain, burning, hypersensitivity, neuropathic symptoms, swelling, or joint complaints involving the affected area.1,2
These features can resemble other dermatologic, vascular, rheumatologic, or neurologic conditions. That can make ACA difficult to recognize, particularly in the United States where clinicians may not expect to encounter it.
What Did the 2026 U.S. Case Series Find?
Giroski and colleagues described three women from Pennsylvania who were diagnosed with ACA based on their clinical findings, skin biopsies, and Lyme serology.1
The most unusual case involved a 71-year-old woman with a four-year history of progressive discoloration of her feet. She reported multiple tick exposures during the preceding 10 to 15 years and had previously tested positive for Lyme antibodies. She had never traveled outside the United States.1
Examination showed red-brown to violaceous sclerotic patches and plaques on both feet. A skin biopsy demonstrated findings supportive of ACA. She was treated with doxycycline 100 mg twice daily for 28 days and reported a substantial reduction in tenderness at the one-month follow-up.1
The absence of international travel is what makes this case particularly noteworthy. Historically, U.S. cases of ACA have often involved patients who had lived in or traveled to Europe, where the Borrelia species most strongly associated with ACA circulate.1
What Happened in the Other Two Patients?
The second patient was an 80-year-old woman with two to three years of painful discoloration involving both feet. She described burning, hypersensitivity, swelling, and allodynia severe enough that even pressure from bed covers could be uncomfortable. She had traveled to Europe, but her most recent trip had occurred eight years before the onset of her skin symptoms.1
Her biopsy showed fibrosis and an inflammatory infiltrate containing plasma cells. She improved substantially with doxycycline, including less erythema and pain and improved ability to wear shoes and resume physical activity. The authors reported recurrence of pain after doxycycline was stopped, followed by improvement after treatment was restarted. Because this is an individual case rather than a controlled treatment study, it cannot establish why symptoms recurred or determine the appropriate duration of antibiotic treatment for other patients.1
The third patient was a 75-year-old woman who developed discoloration involving a foot and ankle as well as a hand. She also had joint swelling. Her only European travel had been a trip to France 19 years before presentation, without a recalled tick bite or erythema migrans during that trip.1
After 28 days of doxycycline, the investigators documented improvement in skin discoloration and joint swelling. She was again able to wear a wedding band that previously had not fit because of swelling.1
Does This Prove ACA Is Being Acquired in the United States?
No. The case series raises that possibility, but it does not prove it.
The strongest evidence comes from the first patient because she reported never traveling outside the United States. However, the investigators were not able to identify the specific Borrelia genotype responsible for infection in any of the three patients.1
That distinction matters. ACA is most commonly associated with Borrelia afzelii and less often with Borrelia garinii, whereas most Lyme disease in the United States is caused by Borrelia burgdorferi sensu stricto.1
The authors discuss several possibilities. A nonendemic Borrelia genotype might occasionally be introduced into the United States, or ACA could represent an extremely uncommon manifestation of Borrelia burgdorferi sensu stricto. The study cannot distinguish among these explanations.1
Can Borrelia Burgdorferi Cause ACA?
Possibly. Although Borrelia burgdorferi sensu stricto is much less commonly associated with ACA than Borrelia afzelii, the relationship is not absolute.
The authors note previous Canadian ACA cases attributed to Borrelia burgdorferi sensu stricto. A large Slovenian study of 693 patients with ACA also found that although Borrelia afzelii accounted for 92.8% of cultured isolates, other species, including Borrelia burgdorferi sensu stricto, were occasionally identified.1,2
That makes it biologically plausible that ACA is not exclusively associated with Borrelia afzelii. It does not, however, establish which organism was responsible for the new Pennsylvania cases.
Why Can ACA Be Missed?
ACA presents very differently from the classic expanding erythema migrans rash that many people associate with early Lyme disease. Patients may instead develop chronic discoloration, swelling, burning, tenderness, or changes in the texture of the skin.
The abnormalities may evolve slowly over months or years. In the new case series, patients had undergone evaluations for other possible explanations before ACA was recognized. One patient had circulatory testing and was evaluated for possible erythromelalgia before dermatologic evaluation and biopsy helped establish the diagnosis.1
This illustrates a broader diagnostic problem with atypical Lyme disease symptoms and unusual rashes: an unfamiliar manifestation may not immediately be connected to a previous tick exposure or Lyme disease.
Does a Positive Lyme Blood Test Prove Someone Has ACA?
No. Lyme antibody testing can support the diagnosis, but a positive test alone does not establish that a chronic skin lesion is ACA.
This was particularly relevant in the case series because some patients had previous positive Lyme tests or a prior Lyme disease diagnosis. Lyme antibodies can remain detectable for years after infection, so seropositivity does not by itself demonstrate that a current skin problem is caused by active Lyme disease.1
The diagnoses in these cases relied on the combination of clinical appearance, history, Lyme serology, and characteristic findings on skin biopsy. This is one reason that Lyme disease testing should be interpreted in the context of the patient’s overall clinical presentation rather than as a stand-alone answer.
What Does This Mean for Patients in the United States?
The report does not suggest that ACA is becoming common in the United States. It remains a very unusual manifestation, and most patients with persistent skin discoloration, swelling, or pain will have other explanations for their symptoms.
But rare does not mean impossible.
The new report is important because automatically excluding ACA solely because a patient has never traveled to Europe could potentially miss an unusual presentation. The appropriate conclusion is not that chronic skin changes after every tick bite represent ACA, but that geography and travel history should be considered alongside the complete clinical picture.
The unanswered microbiologic question is particularly important. Until the infecting Borrelia species or genotype is identified in a domestically acquired U.S. case, we cannot know whether these cases represent an unusual manifestation of endemic Borrelia burgdorferi, introduction of another Borrelia genotype, or another explanation.
Frequently Asked Questions
What does acrodermatitis chronica atrophicans look like?
ACA often begins as slowly progressive reddish-blue, red-brown, or violaceous discoloration and swelling involving an extremity. Over time, the affected skin may become thin, atrophic, or sclerotic. Pain, burning, hypersensitivity, swelling, neuropathic symptoms, or joint complaints can also occur.
Is acrodermatitis chronica atrophicans a form of Lyme disease?
Yes. ACA is a recognized late cutaneous manifestation of Lyme borreliosis. It is much more commonly reported in Europe and is most strongly associated with Borrelia afzelii.
Can you develop ACA without traveling to Europe?
Possibly. A 2026 U.S. case series described a Pennsylvania woman with findings consistent with ACA who reported never traveling outside the United States. However, the infecting Borrelia genotype was not determined, so the case does not establish which organism produced the illness.
Can a Lyme blood test diagnose ACA?
Not by itself. Lyme antibodies can remain positive long after an earlier infection. Diagnosis requires consideration of the skin findings, clinical history, serology, and, when appropriate, skin biopsy findings.
Does ACA improve with antibiotics?
The three patients in the 2026 case series improved after doxycycline treatment, particularly in pain, swelling, or discoloration. However, a three-patient case series cannot determine the optimal treatment duration or predict how another patient will respond.
Clinical Takeaway
Acrodermatitis chronica atrophicans remains extremely uncommon in the United States, but the 2026 case series challenges the assumption that it should be considered only in patients with European exposure. One patient had never traveled outside the United States, while the other two had only remote European travel.
The findings do not establish that Borrelia afzelii is circulating in Pennsylvania, nor do they prove that endemic Borrelia burgdorferi caused these cases. The infecting genotypes were not identified.
For clinicians and patients, the practical message is narrower: an unusual late Lyme skin manifestation should not automatically be excluded solely because there is no history of European travel.
Related Articles
These articles provide additional information about Lyme disease presentations, diagnosis, and less typical manifestations:
Lyme Rash Misdiagnosis: Not Always a Bull’s-Eye
Why Is Lyme Disease Harder to Diagnose Without a Rash?
Delayed Lyme Diagnosis: Why It Happens and Why It Matters
Lyme Disease Misdiagnosis: Why It Happens and What to Know
References
- Giroski J, Flint N, Desrosiers A, Bailiff O, Strickler A, Ferringer T. Case series of acrodermatitis chronica atrophicans in the United States with absent or remote European travel. JAAD Case Reports. 2026;69:36–42.
- Ogrinc K, Maraspin V, Lusa L, et al. Acrodermatitis chronica atrophicans: clinical and microbiological characteristics of a cohort of 693 Slovenian patients. Journal of Internal Medicine. 2021;290(2):335–348.
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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
