Spider veins are predominantly an aesthetic problem. One survey reported telangiectasias of the lower limb as the most concerning cosmetic problem for American women.[7] The majority of patients are asymptomatic; however, a minority of patients who do have symptoms often complain of burning, itching, pain, cramps, or leg fatigue.[7] 

Patients may have one or more mentioned risk factors and could also have a history of chronic venous insufficiency (CVI), including varicose veins or venous eczema. On examination, spider veins can appear as thin blue, red, or purple vessels depending if they are arterial or venous in origin and can be raised or flat. They can form anywhere on the body and at any age, although the majority of patients develop spider veins on their legs and face.

The diagnosis of spider veins is a clinical one based on history and examination. Spider veins feature on the Clinical, Etiological, Anatomical, and Pathological (CEAP) classification system of chronic venous disease, which describes seven categories (C0 –C7).[17]

• C0 - Absence of venous disease
• C1 - Telangiectasias and larger reticular veins.
• C2 - Varicose veins (diameter of 3 mm or more)
• C3 - Edema
• C4 - Changes in the skin and subcutaneous tissue: pigmentation (C4a), eczema (C4a), lipodermatosclerosis (C4b) or atrophic blanche (C4b)
• C5 - Healed venous ulcer
• C6 - Active venous ulcer

Formally, the definition of telangiectasia is a confluence of dilated intradermal venules of less than 1mm in caliber.[17] Another classification by Redisch et al. describes four types of telangiectasias based on their clinical appearance:[18]

1. Simple linear
2. Spider (radiating from a central locus)
3. Arborizing (arranged like branches on a tree)
4. Papular (discrete round spots)

Spider veins are generally harmless and asymptomatic, and the majority of patients seek treatment to reduce or remove them for cosmetic reasons. Treatment includes sclerotherapy, intense pulse light treatment (IPLT), thermocoagulation, and microphlebectomy. Patient factors influence the type of treatments that can be used alone or in combination.

Sclerotherapy

Telangiectasias and reticular veins can be obliterated by injecting sclerosing agents into the vessels. Sclerotherapy is considered to be the first-line treatment for spider veins on the legs. Using ultrasound, the local vasculature is first assessed by examining the deep, superficial, feeder, and perforating veins for obstruction and venous reflux/incompetence. Pathways with an abnormal flow are identified, and the target vessels requiring treatment are marked. The sclerosing agent, which can be a liquid or foam, is injected using a very fine needle (30 gauge) under ultrasound guidance. The agent acts by causing endothelial damage, which leads to vessel fibrosis and an arrest of blood flow. There are numerous sclerosing substances that are currently used in sclerotherapy, and they are classified as detergents, osmotic or chemical irritants.

Detergents such as polidocanol and sodium tetradecyl cause endothelial injury by altering the surface tension around the endothelial cells. Chemical irritants achieve their effect through cauterization; examples include chromated glycerin. Osmotic agents dehydrate endothelial cells. Examples include hypertonic saline and dextrose. In larger reticular veins, foam sclerotherapy may be more appropriate. Foam sclerotherapy involves mixing a fluid such as polidocanol or sodium tetradecyl sulfate with gas to produce the foam. Over time, the vessels fade, are resorbed, and disappear. However, the treatment does not stop new vessels from forming, and multiple treatments may be required to achieve the desired effect. Sclerotherapy is a popular method of treating spider veins, and some studies have reported good improvement in 50% - 70% of patients.[19] Common side effects of sclerotherapy include transient hyperpigmentation, ulceration, sloughing, allergy, thrombophlebitis, swelling, and pain. More serious but rare adverse effects include thromboembolic events, anaphylaxis, and transient visual disturbance. 

Laser Treatment and Intense Pulsed Light (IPL) Treatment

Laser and IPL therapy are non-invasive methods of treating spider veins that have a diameter of less than that of a 30-gauge needle. It is also an option for patients who have spider veins on the face and thus not amenable to sclerotherapy. Patients who are allergic to sclerosing agents or who are needle phobic may also be offered this treatment.

A basic appreciation of laser theory is essential to understand the suitability, limitations, and side effects of this treatment. Laser therapy is delivered via a hand-held device and relies on the target heating up by absorbing energy from photons in the laser. The target will only absorb the photon energy if the laser wavelength matches the chromophore of the target, i.e., the target must be of the appropriate color. It follows that by varying the wavelength of the laser, different chromophores (and therefore different structures) can be selectively targeted while avoiding damage to surrounding tissues.

In spider vein therapy, the light energy is absorbed by hemoglobin in the damaged vessels. The vessels heat up and occlude secondary to thrombus formation by photocoagulation. This concept of selective photolysis was developed by Anderson and Parrish in 1983 and remains the basis of laser therapy in medicine today.[20]

A variety of different lasers are available for the treatment of spider veins, each with their advantages, drawbacks, and specific use.

• Argon laser

Argon lasers were one of the first lasers used for vascular purposes. These lasers produce a blue-green wavelength in the range of 488nm and 514nm. This wavelength means it is well absorbed by hemoglobin and can easily penetrate 1mm into the skin. Some studies have reported success rates of 90% when used in conjunction with sclerotherapy.[21][22] However, argon lasers pose a higher risk of scarring and pigmentation; this is probably the result of its non-specific thermal injury.[22]

• Pulsed dye laser

Pulsed dye lasers, with long wavelengths of 595nm and extended pulse duration of 40ms, have proved useful in the treatment of spider veins.[23] Modern pulsed dye lasers have an integrated cooling device and use pulses shorter than the relaxation time of small vessels (1ms). These characteristics help reduce the risk of unintended thermal damage to surrounding structures, thus reducing scarring and pigmentation. Pulsed dye lasers have shown good clearance with small-caliber vessels; however, their performance with larger caliber vessels has not been as promising.[24][25]

• Neodymium:YAG laser

The longer wavelength of 1064nm of neodymium:YAG (Nd:YAG) lasers make them suitable for larger caliber veins. They are one of the most efficacious lasers in spider vein therapy but may not be the most popular amongst patients due to the discomfort they cause. In addition to the increased pain levels, Nd:YAG lasers can also cause hyperpigmentation.

• Potassium-titanyl-phosphate (KTP) laser

Potassium-titanyl-phosphate (KTP) lasers double the frequency of Nd:YAG lasers by passing the light through a KTP crystal. The resultant light is in the wavelength range of 532nm to 1064nm. This higher frequency makes them suitable for darker skin patients and smaller vessels. They are commonly used on the face as they have limited penetration but are not as efficacious for leg spider veins.

• Pulsed diode laser

Pulsed diode lasers emit photons in the range of 800nm to 900nm. These lasers have an excellent safety profile, which is partly the result of the cooling devices they are equipped with and the fact that they cause minimal inflammatory changes. Pulsed diode lasers have also shown high clearance rates on leg spider veins in numerous studies.[26][27]

Overall, lasers are safe and efficacious methods of treating spider veins. They are non-invasive and are a popular choice for patients with face spider veins or who are needle phobic. Other side effects of laser therapy include blistering, crusting, swelling, and spotting. Contraindications to laser therapy include pregnancy, blood-thinning medication, photosensitive or hypertrophic/keloidal scarring disorders, untreated varicose veins, and in some cases, recent tanning or dark skin type.

Microphlebectomy

Microphlebectomy uses hooks for venous extraction via minute skin incisions (1-3mm) or needle punctures. Microphlebectomy avoids the complications of other treatments such as scarring, skin necrosis, and residual hyperpigmentation.[28]  

Thermocoagulation

Similar to other methods of treatment, thermocoagulation achieves its effect by causing endothelial damage to the target vessel. The heat generated from a very high frequency (radio frequency) pulse is transmitted to the vessel through a very small needle inserted into the target vessel. When the temperature reaches 70 degrees Celsius, the vessel is occluded through thermocoagulation. The vessel is eventually resorbed and fades away.

Spider veins can be associated with CVI, and other stigmas of CVI, such as varicose veins, venous eczema of the skin, stasis dermatitis, and leg ulcers may be present.[29][30] These conditions are more severe and warrant medical attention before addressing spider veins, which are often purely a cosmetic problem. Spider veins cans can also be an early sign of CVI, and clinicians must be weary of undiagnosed CVI in patients presenting with spider veins.

Spider angiomas can also masquerade as spider veins. They are harmless, but they often herald more serious systemic diseases such as rheumatoid arthritis, thyroid, and liver disease.[31] They have a similar appearance to spider veins, with the exception that they have a central red spot with radiating web-like extensions.

Untreated spider veins remain a purely cosmetic issue and do not cause any significant medical problems or functional impairment. In severe cases affecting the legs or face, they can affect the patient’s self-esteem and lead to psychological issues, particularly in young females who are more body-conscious.

Complications from untreated spider veins are infrequent and do not usually cause any health problems. In severe cases associated with varicose veins, there is a higher chance of developing sores or skin ulcers, and thrombophlebitis. As with any procedure, there are risks of complications, and therapeutic procedures for spider veins are no exceptions; however, these risks are very low.

Naturally, there is little that can be done to address non-modifiable risk factors such as age, sex, ethnicity, and gravidity. Measures can be taken to address other factors such as maintaining a normal BMI, smoking cessation, keeping active, and avoiding tight clothing proximal to the spider veins. There is some evidence to suggest that compression stockings may be of some benefit in preventing new spider veins from forming after treatment.[32]

As a purely cosmetic problem, spider veins warrant input from an interprofessional team involved in aesthetic medicine, including dermatologists, aestheticians, and plastic surgeons. Patients may first present to their general practitioner, who then refers them on to a dermatologist or plastic surgeon. In many healthcare economies, spider vein treatment is considered as aesthetic; thus, government or insurance funding may be limited, but a significant commercial market exists, and the astute practitioner will counsel patients to seek care with reputable aesthetic medicine providers. The treating practitioner must have an honest and frank discussion with the patient about the aims, risks, and benefits, and out-of-pocket costs of any treatment plan, and allow the patient to make an informed decision.