Changes

July 2024 — reviewed. A literature search was conducted in June 2024 to identify evidence-based guidelines, UK policy, systematic reviews, and key randomized controlled trials published since the last revision of this topic. The recommendations have been updated in line with current evidence in the literature, including to consider arranging urgent duplex ultrasound scan if there is suspected superficial vein thrombosis of the lower limb. Minor structural changes have been made to improve clarity and navigation.

Update

Goals

To support primary healthcare professionals to:

• Assess a person with suspected superficial vein thrombosis (SVT).
• Make a working diagnosis of SVT. 
• Advise on symptom relief and self-care measures for SVT.
• Identify and manage any complications of SVT.
• Arrange vascular surgery or other specialist referral if clinically indicated.

Outcome measures

Audit criteria

No audit criteria were found during the review of this topic.

QOF indicators

QIPP - Options for local implementation

No QIPP indicators were found during the review of this topic.

NICE quality standards

What is it?

• Superficial vein thrombosis (SVT, also known as 'superficial thrombophlebitis' or 'superficial phlebitis') describes inflammation of the superficial vein system associated with venous thrombosis [Cosmi, 2015; Nasr, 2015; Almeida, 2019; Kakkos, 2021].
  • SVT of the lower limb typically involves the long or short saphenous veins or their branches [Tait, 2012].
  • SVT can also affect superficial veins in other parts of the body, such as the upper limbs, abdominal or thoracic wall, or neck [Cosmi, 2015]. These are outside the scope of this CKS topic.
• Migratory thrombophlebitis describes recurrent SVT that develops at varying or multiple sites, but most commonly in the lower limb [Nasr, 2015; Scott, 2015; Almeida, 2019].

What are the risk factors?

Most cases of superficial vein thrombosis (SVT) are spontaneous, usually in people with varicose veins. It can also result from venous stasis or injury or trauma to normal veins or varicosities [Kakkos, 2021]. Risk factors include:

• Varicose veins — the most common risk factor for lower limb SVT [Cosmi, 2015] [Nasr, 2015] [Almeida, 2019].
  • Varicose veins are present in 80–90% of people with SVT, with or without evidence of chronic venous insufficiency [Cosmi, 2015].
  • Venous stasis inside the varicosities or the dilated and incompetent main saphenous trunks results in thrombus formation that may extend into adjacent veins, including the deep venous system causing deep vein thrombosis (DVT) [Kakkos, 2021].
• Other risk factors for SVT are similar to those for DVT [Di Minno, 2016; Tait, 2012; Cosmi, 2015]:
  
  • Increasing age [Mangiafico, 2024].
  • Obesity.
    • There is a 2.6-fold increased risk of SVT in people who are overweight compared with people who are not, independent of the presence of varicose veins [de Moerloose, 1998].
  • Active cancer.
    • Unprovoked SVT of a normal vein may be the result of malignancy [Kakkos, 2021]. Pancreatic cancer, for example, may cause recurrent SVT at different sites without an identifiable local cause (so-called migratory thrombophlebitis or Trousseau syndrome) [Cosmi, 2015; Nasr, 2015; Scott, 2015].
    • SVT is likely to be due to the pro-inflammatory and hypercoagulable state of malignancy [Vidal, 2024].
  • Previous SVT or venous thromboembolism (VTE) [Nasr, 2015].
  • Pregnancy and the puerperium (up to 6 weeks postpartum).
    • This may be due to an increase in procoagulant factors and reduced fibrinolytic activity. Venous dilation and the resulting venous stasis, particularly in the third trimester, is also a risk factor during pregnancy [Tait, 2012; Nasr, 2015].
    • In a Danish cohort study, the estimated prevalence of SVT in pregnancy was about 0.1%, with an increased incidence rate in the postpartum period of 1.6 per 1000 person-years [Wiegers, 2023].
  • Oral contraception and hormone replacement therapy (HRT) use.
    • There is a 2- to 6-fold increased relative risk of venous thrombotic events (including SVT) in oral contraceptive users and a 2- to 4-fold increased risk among oral HRT users [Mangiafico, 2024].
  • Intravenous cannulation and infusion.
    • This may result from catheter insertion, venipuncture, or intravenous drug infusion. The duration of catheterization, catheter-related infection, and catheter material are important risk factors for infusion-related SVT, including use of irritants in sclerotherapy treatment for varicose veins [Nasr, 2015; Cosmi, 2015].
  • Prolonged immobility and/or recent surgery.
    • Prolonged immobilization may predisposes to venous stasis and/or hypercoagulability of blood [Nasr, 2015].
  • Autoimmune disease (particularly Behcet's and Buerger's disease).
    
    • SVT of a normal vein may be caused by systemic prothrombotic conditions such as rheumatological or inflammatory diseases, including systemic lupus erythematosus, Behcet's disease, and Buerger’s disease (thromboangiitis obliterans), which predispose to recurrent SVT [Kakkos, 2021].
    • Over 50% of people with Behcet's disease will experience an episode of SVT, usually within 5 years of diagnosis (rarely it precedes the diagnosis of Behcet's) [Sarica-Kucukoglu, 2006].
  • A coagulation disorder.
    • SVT of a normal vein may be the result of thrombophilia [Kakkos, 2021]. These include protein C or S deficiency and Factor V Leiden mutation [Tait, 2012; Nasr, 2015]. There is no evidence that thrombophilia influences the rates of SVT recurrence or progression [Tait, 2012].

How common is it?

Superficial vein thrombosis (SVT) is relatively common and mainly affects the lower limbs. The true incidence is likely to be underestimated in the general population, and varies depending on the study population, methodology, and care setting [Mangiafico, 2024].

• Expert opinion in a review article cites studies which estimate the incidence ranges from about 0.3 to 1.5 events per 1000 person-years, with incidence increasing with age, and prevalence of approximately 3–11% depending on the population studied [Mangiafico, 2024].
• A retrospective cohort primary care study with 3-month follow-up found [Geersing, 2018]:
  • An estimated incidence rate of SVT of 1.31 per 1000 person-years follow-up, with higher rates with increasing age.
  • A total cumulative incidence of 4.1% had complications of VTE at diagnosis or during follow-up.
• A prospective observational study of ultrasound-confirmed acute isolated SVT (n = 1150) found  [Bauersachs, 2021]:
  • Below-the-knee SVT in 54.5% of participants.
  • Above-the-knee SVT in 26.7% of participants.
  • Above- and below-the-knee SVT in 18.8% of participants.
• Expert opinion in a review article notes an increased incidence of SVT in women [Nasr, 2015].

What are the complications?

The risks from superficial vein thrombosis (SVT) are related to the precise location and length of the thrombus in the superficial veins [Kakkos, 2021]. Possible complications include venous thromboembolism (VTE), and SVT recurrence or extension.

VTE risk, SVT recurrence and extension

• A prospective observational study of adults with ultrasound-confirmed acute isolated SVT (n = 1150; 93.2% receiving anticoagulation) followed up at 3 months found [Bauersachs, 2021]:
  • Complete clinical recovery of SVT was reported in 708 participants (62.4%).
  • 4.7% had recurrent or extended SVT; 1.7% had reported deep vein thrombosis (DVT); and 0.8% had reported pulmonary embolism (PE).
• A French prospective study of 844 consecutive cases of ultrasound-confirmed symptomatic SVT measuring at least 5 cm in length reported [Decousus, 2010]:
  • 24.9% of cases had evidence of concurrent VTE at diagnosis (3.9% with symptomatic PE; 9.7% with proximal DVT; 11.3% with distal DVT). In 58% of cases, the DVT was contiguous with the segment of SVT.
  • 10.2% of cases without complications at diagnosis had thromboembolic complications at 3 months follow-up (0.5% had PE; 2.8% had DVT; 3.3% had extension of SVT; 1.9% had recurrence of SVT), despite 90.5% of participants receiving anticoagulation.
• In a French multicentre, community-based study (n = 171) of people with symptomatic ultrasound-confirmed SVT [Frappe, 2014]:
  • The annual diagnosis rate was 0.64%, and was higher in women and increased with age.
  • Concomitant DVT and PE was found in 24.6% and 4.7% of cases respectively.
  • There was an increased risk of VTE complications if the SVT involved the great saphenous vein or was located at or above the knee and/or extended to the perforating veins.
• Similarly, in a large meta-analysis of 21 studies (n = 4358 evaluating the presence of DVT) and 11 studies (n = 2484 evaluating the presence of PE) [Di Minno, 2016]:
  • The weighted mean prevalence of concurrent DVT and PE at diagnosis of SVT was 18.1% and 6.9% respectively. The authors acknowledged the heterogeneous nature of the studies included.
• A British Journal of Haematology guideline states that concomitant DVT is less likely with SVT at the site of an existing varicose vein, but more likely if the SVT involves the main trunk of a saphenous vein (rather than its branches), particularly the proximal long saphenous vein if adjacent to the saphenofemoral junction or within 10 cm of it. It also notes that isolated SVT (without concomitant DVT) may still progress to DVT [Tait, 2012].
• Expert opinion in a review article cites evidence that the overall 3-month mortality rate for SVT is less than 1% [Cosmi, 2015].

Infection

• Infection — this may occur, particularly if SVT is the result of intravenous cannulation. It may lead to abscess formation and may spread, with a risk of cellulitis and/or sepsis [Cosmi, 2015; Nasr, 2015]. See the CKS topics on Cellulitis - acute and Sepsis for more information.

What is the prognosis?

There is a risk of progression to venous thromboembolism (VTE) for at least 3 months after superficial vein thrombosis (SVT) is diagnosed [Kakkos, 2021].

• In a duplex ultrasound follow-up study of 263 cases of untreated isolated SVT, 11% had progressed to deep vein thrombosis (DVT) within 10 days, most commonly with progression from the greater saphenous vein in the thigh into the common femoral vein [Chengelis, 1996].
• A prospective observational study of 586 cases of isolated SVT given low molecular weight heparin (LMWH) therapy (63% full dose, 37% prophylactic dose; median duration 11 days) found [Decousus, 2010]:
  • 10.2% had further venous thrombosis (0.5% symptomatic pulmonary embolism [PE], 2.8% symptomatic DVT, 3.3% SVT extension, 1.9% recurrent SVT) during the first 3 months of follow-up.
• A longer term observational multicentre study of 411 consecutive outpatients with symptomatic isolated SVT followed up for a median of 3 years found [Barco, 2017]:
  • Symptomatic DVT or PE occurred in 12.9% of participants, representing an annual rate of 1.3% on anticoagulation, and 4.4% annual rate after anticoagulation was discontinued.
• Risk factors for SVT extension, recurrence, or progression to DVT include:
  • SVT within 10 cm of the saphenofemoral junction at thigh level [Decousus, 2010; Kakkos, 2021].
  • SVT length more than 5 cm [Kakkos, 2021; Riat, 2022].
  • Extensive SVT involving both the calf and the thigh [Twine, 2023].
  • Occurrence in men [Decousus, 2010; Barco, 2017].
  • History of VTE [Decousus, 2010].
  • History of active or recent cancer [Decousus, 2010; Barco, 2017; Kakkos, 2021].
  • Absence of varicose veins [Decousus, 2010].
  • Presence of severe chronic venous insufficiency [Decousus, 2010].

When should I suspect a diagnosis of superficial vein thrombosis?

Superficial vein thrombosis (SVT) is usually a clinical diagnosis with visible inflammation of the vein walls and surrounding tissues.

• Suspect a diagnosis of SVT of the lower limb if a person presents with:
  • A red, tender, palpable, firm lump or cord typically, but not always, located in an area of pre-existing varicose veins, particularly along a segment of the great saphenous vein.
    • There may be associated itch, warmth, and swelling of the surrounding tissues.
    • There may be haemosiderin-based brown pigmentation over the affected superficial veins developing over days to weeks.

How should I assess a person with suspected superficial vein thrombosis?

If a person has a suspected diagnosis of superficial vein thrombosis (SVT):

• Ask about:
  • Any symptoms such as pain or itch, their onset, duration, severity, impact on daily functioning, and any aggravating or relieving factors.
    • Symptoms typically develop over hours to days, and resolve in days to weeks, although hardness of the vein may persist for longer (several weeks to months).
  • Any risk factors for SVT such as varicose veins or symptoms of complications such as venous thromboembolism (VTE).
  • Any previous episodes of SVT or VTE, or features suggesting migratory thrombophlebitis.
  • Any family history of VTE or heritable coagulopathy.
  • Any previous treatments tried.
• Examine both legs when the person is standing.
  • Examine for a tender, hard vein or palpable cord associated with warmth and possible erythema or brown pigmentation along the course of a superficial vein, and measure the length of vein affected.
  • Assess the location and severity of any varicose veins or other signs of chronic venous insufficiency, venous leg ulcer, skin pigmentation, or oedema. See the CKS topics on Leg ulcer - venous, Varicose veins, and Venous eczema and lipodermatosclerosis for more information.
  • Assess for signs of a complication such as VTE or infection.
• Consider arranging admission or referral for an urgent venous duplex ultrasound scan to confirm the diagnosis, depending on local referral pathways and clinical judgement, particularly if:
  • There is suspected SVT affecting the proximal long saphenous vein.
  • There is suspected SVT at the saphenofemoral junction at thigh level.
  • There is extensive SVT, for example measuring 5 cm or more, or affecting both the thigh and the calf.
  • The diagnosis is uncertain.
• Do not use a D-dimer blood test to diagnose suspected SVT.
• Consider whether there is an alternative diagnosis or concurrent condition such as deep vein thrombosis (DVT). See the section on Differential diagnosis for more information.

What else might it be?

• Alternative conditions which may present similarly or concurrently with superficial vein thrombosis (SVT) include:
  • Deep vein thrombosis (DVT). See the CKS topic on Deep vein thrombosis for more information.
  • Panniculitis — a group of conditions that involve inflammation of the subcutaneous fat.
  • Skin infection (erysipelas or cellulitis). See the CKS topic on Cellulitis - acute for more information.
  • Chronic venous insufficiency. See the CKS topics on  Leg ulcer - venous, Varicose veins, and Venous eczema and lipodermatosclerosis for more information.
  • Insect bite or stings. See the CKS topics on Insect bites and stings for more information.
  • Lymphangitis — infection and inflammation of the lymphatic vessels; typically presents with warm, enlarged, and tender lymph nodes in the inguinal area.
  • Lyme disease. See the CKS topic on Lyme disease for more information.
  • Tendonitis. See the CKS topics on Achilles tendinopathy and Sprains and strains for more information.
  • Vasculitic conditions (such as erythema nodosum and polyarteritis nodosum) — characterized by inflammation within or around blood vessels, with or without necrosis. May present with palpable, painful purpura usually on the lower leg or buttock, and systemic signs.

Scenario: Management of superficial vein thrombosis

From age 16 years onwards.

Search strategy

Scope of search

A literature search was conducted for guidelines and systematic reviews on primary care management of superficial thrombophlebitis.

Search dates

January 2020 - June 2024

Key search terms

The terms listed below are the core search terms that were used for EBSCOhost MEDLINE (searched July 2024). These were combined with filters to identify guidelines, systematic reviews and primary care relevant literature in EBSCOhost MEDLINE. The strategy was adapted for The Cochrane Library databases. 

S5    S1 OR S2 OR S3 OR S4 
S4    AB ( mondor or mondor's ) OR TI ( mondor or mondor's ) 
S3    AB phlebitis OR TI phlebitis 
S2    AB (superficial venous thrombosis OR superficial vein thrombosis) OR TI (superficial venous thrombosis OR superficial vein thrombosis)
S1    (MH "Thrombophlebitis+") 

Sources of guidelines

• National Institute for Health and Care Excellence (NICE)
• Scottish Intercollegiate Guidelines Network (SIGN)
• Royal College of Physicians
• Royal College of General Practitioners
• Royal College of Nursing
• NICE Evidence
• World Health Organization
• Guidelines International Network
• TRIP database
• Agency for Healthcare Research and Quality
• Institute for Clinical Systems Improvement
• National Health and Medical Research Council (Australia)
• Royal Australian College of General Practitioners
• British Columbia Medical Association
• Canadian Medical Association
• Alberta Medical Association
• Michigan Quality Improvement Consortium
• Singapore Ministry of Health
• National Resource for Infection Control
• RefHELP NHS Lothian Referral Guidelines
• Medline (with guideline filter)
• Driver and Vehicle Licensing Agency
• NHS Health at Work (occupational health practice)

Sources of systematic reviews and meta-analyses

• The Cochrane Library:
  • Systematic reviews
  • Protocols
  • Database of Abstracts of Reviews of Effects
• Medline (with systematic review filter)
• EMBASE (with systematic review filter)

Sources of health technology assessments and economic appraisals

• NIHR Health Technology Assessment programme
• The Cochrane Library:
  • NHS Economic Evaluations
  • Health Technology Assessments
• Canadian Agency for Drugs and Technologies in Health
• International Network of Agencies for Health Technology Assessment

Sources of randomized controlled trials

• The Cochrane Library:
  • Central Register of Controlled Trials
• Medline (with randomized controlled trial filter)
• EMBASE (with randomized controlled trial filter)

Sources of evidence based reviews and evidence summaries

• Bandolier
• Drug and Therapeutics Bulletin
• TRIP database
• Central Services Agency COMPASS Therapeutic Notes

Sources of national policy

• Department of Health
• Health Management Information Consortium (HMIC)

Patient experiences

• Healthtalk
• BMJ - Patient Journeys

Sources of medicines information

The following sources are used by CKS pharmacists and are not necessarily searched by CKS information specialists for all topics. Some of these resources are not freely available and require subscriptions to access content.

• British National Formulary (BNF)
• electronic Medicines Compendium (eMC)
• European Medicines Agency (EMEA)
• LactMed
• Medicines and Healthcare products Regulatory Agency (MHRA)
• REPROTOX
• Scottish Medicines Consortium
• Stockley's Drug Interactions
• TERIS
• TOXBASE
• Micromedex
• UK Medicines Information

Stakeholder engagement

Our policy

The external review process is an essential part of CKS topic development. Consultation with a wide range of stakeholders provides quality assurance of the topic in terms of:

• Clinical accuracy.
• Consistency with other providers of clinical knowledge for primary care.
• Accuracy of implementation of national guidance (in particular NICE guidelines).
• Usability.

Principles of the consultation process

• The process is inclusive and any individual may participate.
• To participate, an individual must declare whether they have any competing interests or not. If they do not declare whether or not they have competing interests, their comments will not be considered.
• Comments received after the deadline will be considered, but they may not be acted upon before the clinical topic is issued onto the website.
• Comments are accepted in any format that is convenient to the reviewer, although an electronic format is encouraged.
• External reviewers are not paid for commenting on the draft topics.
• Discussion with an individual or an organization about the CKS response to their comments is only undertaken in exceptional circumstances (at the discretion of the Clinical Editor or Editorial Steering Group).
• All reviewers are thanked and offered a letter acknowledging their contribution for the purposes of appraisal/revalidation.
• All reviewers are invited to be acknowledged on the website. All reviewers are given the opportunity to feedback about the external review process, enabling improvements to be made where appropriate.

Stakeholders

• Key stakeholders identified by the CKS team are invited to comment on draft CKS topics. Individuals and organizations can also register an interest to feedback on a specific topic, or topics in a particular clinical area, through the Getting involved section of the Clarity Informatics website.
• Stakeholders identified from the following groups are invited to review draft topics:
  • Experts in the topic area.
  • Professional organizations and societies (for example, Royal Colleges).
  • Patient organizations, Clarity has established close links with groups such as Age UK and the Alzheimer’s Society specifically for their input into new topic development, review of current topic content and advice on relevant areas of expert knowledge.
  • Guideline development groups where the topic is an implementation of a guideline.
  • The British National Formulary team.
  • The editorial team that develop MeReC Publications.
• Reviewers are provided with clear instructions about what to review, what comments are particularly helpful, how to submit comments, and declaring interests.

Patient engagement

Clarity Informatics has enlisted the support and involvement of patients and lay persons at all stages in the process of creating the content which include:

• Topic selection
• Scoping of topic
• Selection of clinical scenarios
• First draft internal review
• Second draft internal review
• External review
• Final draft and pre-publication

Our lay and patient involvement includes membership on the editorial steering group, contacting expert patient groups, organizations and individuals.

Evidence exclusion criteria

Our policy

Scoping a literature search, and reviewing the evidence for CKS is a methodical and systematic process that is carried out by the lead clinical author for each topic. Relevant evidence is gathered in order that the clinical author can make fully informed decisions and recommendations. It is important to note that some evidence may be excluded for a variety of reasons. These reasons may be applied across all CKS topics or may be specific to a given topic.

Studies identified during literature searches are reviewed to identify the most appropriate information to author a CKS topic, ensuring any recommendations are based on the best evidence. We use the principles of the GRADE and PICOT approaches to assess the quality of published research. We use the principles of AGREE II to assess the quality of published guidelines.

Standard exclusions for scoping literature:

• Animal studies
• Original research is not written in English

Possible exclusions for reviewed literature:

• Sample size too small or study underpowered
• Bias evident or promotional literature
• Population not relevant
• Intervention/treatment not relevant
• Outcomes not relevant
• Outcomes have no clear evidence of clinical effectiveness
• Setting not relevant
• Not relevant to UK
• Incorrect study type
• Review article
• Duplicate reference

Organizational, behavioural and financial barriers

Our policy

The CKS literature searches take into consideration the following concepts, which are discussed at the initial scoping of the topic.

• Feasibility
  • Studies are selected depending on whether the intervention under investigation is available in the NHS and can be practically and safely undertaken in primary care.
• Organizational and Financial Impact Analysis
• Studies are selected and evaluated on whether the intervention under investigations may have an impact on local clinical service provision or national impact on cost for the NHS. The principles of clinical budget impact analysis are adhered to, evaluated and recorded by the author. The following factors are considered when making this assessment and analysis.
  • Eligible population
  • Current interventions
  • Likely uptake of new intervention or recommendation
  • Cost of the current or new intervention mix
  • Impact on other costs
  • Condition-related costs
  • In-direct costs and service impacts
  • Time dependencies
• Cost-effectiveness or cost-benefit analysis studies are identified where available. 

We also evaluate and include evidence from NICE accredited sources which provide economic evaluations of recommendations, such as NICE guidelines. When a recommended action may not be possible because of resource constraints, this is explicitly indicated to healthcare professionals by the wording of the CKS recommendation.

Declarations of interest

Our policy

Clarity Informatics requests that all those involved in the writing and reviewing of topics, and those involved in the external review process to declare any competing interests. Signed copies are securely held by Clarity Informatics and are available on request with the permission of the individual. A copy of the declaration of interest form which participants are asked to complete annually is also available on request. A brief outline of the declarations of interest policy is described here and full details of the policy is available on the Clarity Informatics website. Declarations of interests of the authors are not routinely published, however competing interests of all those involved in the topic update or development are listed below. Competing interests include:

• Personal financial interests
• Personal family interest
• Personal non-financial interest
• Non-personal financial gain or benefit

Although particular attention is given to interests that could result in financial gains or losses for the individual, competing interests may also arise from academic competition or for political, personal, religious, and reputational reasons. An individual is not obliged to seek out knowledge of work done for, or on behalf of, the healthcare industry within the departments for which they are responsible if they would not normally expect to be informed.

Who should declare competing interests?

Any individual (or organization) involved in developing, reviewing, or commenting on clinical content, particularly the recommendations should declare competing interests. This includes the authoring team members, expert advisers, external reviewers of draft topics, individuals providing feedback on published topics, and Editorial Steering Group members. Declarations of interest are completed annually for authoring team and editorial steering group members, and are completed at the start of the topic update and development process for external stakeholders.

Competing interests declared for this topic:

None.