Carotidynia is a syndrome characterized by pain and tenderness at the carotid bifurcation. It is also called Fay syndrome. The official name is TIPIC (Transient Perivascular Inflammation of the Carotid artery) syndrome.
In 1927, Temple Fay first reported it as atypical facial neuralgia1)2). Subsequently, in 1988, the International Headache Society (IHS) included it in the headache classification as a type of vascular headache. However, in 2004, it was removed due to “insufficient specificity and consistency”1)4). In 2017, Lecler et al. proposed “TIPIC syndrome” based on an analysis of 47 cases and recommended its inclusion in ICHD-III4).
The exact prevalence is unknown. One report found it in 2.8% of patients with acute neck pain2)4). The typical age of onset is the 40s to 50s (4th to 5th decade), with a female predominance of 1.5:15).
Ophthalmological associations include Horner syndrome, Adie tonic pupil, ptosis, and sluggish pupillary response associated with TIPIC.
They describe the same condition under different names in different eras. Fay first reported it as carotidynia in 1927, IHS classified it in 1988 and removed it in 2004, and Lecler et al. redefined it as TIPIC syndrome in 2017 based on 47 cases1)4). Currently, both terms are used interchangeably.
The main symptom is unilateral neck pain localized to the area of the carotid bifurcation.
In addition to radiating pain to the eye, Horner syndrome, Adie tonic pupil, ptosis, and sluggish pupillary response have been reported. This is thought to be due to inflammation around the carotid bifurcation affecting the sympathetic nervous system. Neck pain with ocular abnormalities should include this condition in the differential diagnosis.
The exact cause and risk factors are not known. Several triggers have been reported in case studies.
Multiple cases of TIPIC after mRNA vaccination (Pfizer-BioNTech, Spikevax) have been reported3)6). Neck pain appeared around one week after vaccination and improved with NSAID treatment. The mechanism is presumed to involve molecular mimicry, specific autoantibody production, or vaccine adjuvant involvement, but a TIPIC-specific immune pattern has not been identified3).
Diagnosis of TIPIC requires meeting all four major criteria below2)4).
An auxiliary criterion is the presence of a spontaneously resolving intimal soft plaque 10).
Historically, the IHS 1988 criteria used four items: ① pain, swelling, and increased pulsation on compression, ② exclusion of structural causes, ③ spontaneous resolution within 14 days, and ④ unilateral neck pain that may radiate to the head.
The characteristics of imaging modalities are shown below.
| Modality | Key Findings | Features |
|---|---|---|
| Ultrasound (first-line) | Eccentric hypoechoic wall thickening, hyperechoic perivascular fat | Non-invasive, Doppler allows hemodynamic assessment |
| MRI | Perivascular enhancement on contrast-enhanced T1, high signal on STIR/T2, intimal preservation | 3T high resolution allows detailed evaluation of wall thickening |
| CT/CTA | Adventitial thickening, contrast enhancement | Useful for excluding dissection and aneurysm. Stenosis is atypical |
| 18FDG-PET | Abnormal accumulation around the carotid artery wall | Supports inflammation; also useful for differentiating tumors and systemic diseases |
On ultrasound, eccentric lesions are found in 83.3% of cases, and 58.3% are localized to the CCA wall or bulb 4)5). Luminal stenosis is usually absent, and there are no significant changes in Doppler hemodynamics 2). MRI shows that the intima is preserved, and inflammation extends to the adventitia and media 9). DWI (diffusion-weighted imaging) has been reported to show restricted diffusion in perivascular tissues, which may be useful as a diagnostic aid 10).
In the report by Upton (2003), lymphocyte infiltration, scattered neutrophils, and fibrosis were observed. Vascular and fibroblast proliferation with nonspecific inflammatory findings were present, with no evidence of tumor, infection, granuloma, giant cells, or vasculitis2)5).
Vascular Differential
Carotid artery dissection: May present with sudden pain and Horner syndrome. Intramural hematoma is confirmed on MRI.
Giant cell arteritis (GCA): Common in elderly. Elevated ESR and CRP, headache, temporal artery thickening.
Fibromuscular dysplasia: Common in young women. “Beaded” appearance on angiography.
Aneurysm and intramural hematoma: Confirm morphological abnormalities on imaging.
Non-vascular differential diagnoses
Cervical abscess and lymphadenitis: Fever, leukocytosis, signs of infection.
Thyroiditis: Differentiate with thyroid function tests and ultrasound.
Eagle syndrome / hyoid bone anomaly: X-ray/CT shows elongated styloid process.
Migraine / trigeminal neuralgia: No abnormality on carotid imaging. Differentiated by headache recurrence and pattern.
TIPIC is a self-limiting disease, and most cases resolve spontaneously within 7–14 days. The median time to symptom resolution is 13 days (Lecler et al., 48 cases)4), and the mean is 17 days (Micieli et al., 72 cases, multinational study)4)5).
A wide range of NSAIDs are used for symptom relief. Main examples are shown below.
| Drug name | Dosage and administration | Report |
|---|---|---|
| Ibuprofen | 600 mg 3 times/day for 7 days, then 400 mg 3 times/day for 7 days | Greutert 20245) |
| Ibuprofen | 400 mg twice daily for 3–4 weeks | Peycheva 20244) |
| Naproxen | 500 mg twice daily | Ferreira 20258) |
| Etodolac | 400 mg twice daily | Ari 20257) |
| Dexketoprofen | 50 mg/day for 5 days | Ulus 20226) |
Used when NSAIDs are ineffective. A reported regimen starts with prednisone 40 mg and tapers by 5 mg per week 3).
When imaging shows luminal stenosis, low-dose aspirin 81–100 mg/day may be added 7)8).
Rest, local warm compresses, and avoidance of pressure on the affected artery are recommended 5).
The prognosis is generally good, with the majority achieving complete recovery. The recurrence rate is 18.6–20%, with the peak recurrence occurring within the first two weeks 4). Many recurrent cases are associated with autoimmune diseases. Follow-up at 14 days, 90 days, and 1 year is recommended; Peycheva et al. propose imaging evaluation every 6–12 months for the first 5 years and annually thereafter 4).
The recurrence rate is 18.6–20%, and NSAID treatment is effective for recurrences as it is for the initial episode 4). If recurrences are frequent, autoimmune diseases are often associated, so immunological workup is recommended. Peycheva et al. propose follow-up every 6–12 months for the first 5 years 4).
The pathology of TIPIC is inflammation of the vessel and perivascular tissue at the level of the carotid bifurcation. Usually, there is no luminal stenosis and normal blood flow is maintained. Inflammation involves the adventitia and media, while the intima is preserved 9).
Histology (Upton 2003) shows lymphocytic infiltration, scattered neutrophils, and fibrosis, with evidence of vascular and fibroblast proliferation. The absence of granulomas, giant cells, and vasculitis is characteristic of this disease 5). Early fibrosis and vascular proliferation may suggest a chronic course 4).
After acute inflammation resolves, residual wall thickening on ultrasound may persist as a “scar” 9).
Regarding inflammatory markers, soluble ICAM-1 (sICAM-1, a marker of large-vessel vasculitis activity) has been reported to correlate with the clinical stage of TIPIC 8).
Venetis et al. (2022) reported a case of TIPIC occurring 2 weeks after COVID-19 (alpha variant) infection 9). 18FDG-PET/CT showed marked FDG uptake around the left common carotid artery, and MRI revealed gadolinium enhancement of the pericarotid soft tissue. Inflammation involved the adventitia and media, while the intima was preserved. Without treatment, regression on ultrasound began after 7 days, and residual wall thickening (scar) was confirmed after 16 weeks.
The mechanism of COVID-19-associated TIPIC is presumed to involve SARS-CoV-2 infecting endothelial cells via ACE2 receptors, leading to direct invasion of the carotid body (blood flow 200 mL/100g/min) and causing inflammatory aggregates, microthrombi, and microhemorrhages 3). For post-mRNA vaccine cases, molecular mimicry, production of specific autoantibodies, and involvement of vaccine adjuvants are hypothesized, but a TIPIC-specific immune pattern has not been identified 3).
Multiple cases of TIPIC after SARS-CoV-2 infection have been reported, and it is being positioned as one of the intravascular and perivascular inflammatory thrombotic complications of COVID-199)3).
Sandу et al. (2023) reported a 49-year-old woman who developed TIPIC 7 days after the second dose of Spikevax (mRNA-1273)3). CRP was 16 mg/L, and STIR hyperintensity was confirmed on MRI. She was treated with prednisone 40 mg (tapered by 5 mg per week) plus aspirin, and wall thickening decreased to 1.1 mm after 3 months. After 6 months, mild recurrence (2.5 mm) occurred following an upper respiratory tract infection, and it regressed to 1.4 mm after 9 months.
Ulus et al. (2022) reported a 39-year-old man who developed TIPIC one week after receiving the Pfizer-BioNTech (BNT162b2) vaccine and experienced recurrence after the second dose6). He was treated with dexketoprofen 50 mg/day for 5 days, and symptoms resolved after 10 days. Ultrasound at 1.5 months showed complete resolution of wall thickening.
Evaluation of perivascular inflammation in TIPIC using diffusion-weighted imaging (DWI) is a new area of research.
Maggialetti et al. (2022) first reported diffusion restriction in the perivascular tissue of TIPIC on DWI sequences of MRI 10). After three weeks of NSAID treatment, both ultrasound and MRI confirmed resolution. This suggests that DWI may be a useful new modality for diagnosis and monitoring of treatment response.
Rare cases of TIPIC with antiphospholipid antibodies have been reported.
Ferreira et al. (2025) reported a case of TIPIC positive for anticardiolipin antibodies and anti-β2GPI IgM 8). The patient was managed with naproxen plus aspirin 100 mg and hydroxychloroquine 200 mg. PET/CT showed FDG uptake in the pericarotid soft tissue, and sICAM-1 correlated with disease activity.
In 2019, Lecler et al. proposed the inclusion of TIPIC in ICHD-III 2). Long-term recurrence rates are 18.6–20%, and recurrent cases often have comorbid autoimmune diseases, so regular follow-up for the first five years has been suggested 4). Establishing the disease concept internationally and developing standard treatment protocols remain future challenges.
