She is right that you should have the reticular veins that drive the spider veins treated. Without doing that, the spider veins are likely to recur. The spider veins are in the skin, the reticular veins are under the skin. The reticular veins are not, however the "main veins". These have names like greater, lesser saphenous or perforating veins. When the treatment involves these veins, things can start to get dangerous. The danger comes from blocking off major outflow veins or from producing thrombosis in the deep venous system (DVT or Deep Venous Thrombosis). A sclerotheraputic agent that will not cause these larger veins to thrombose is a real advantage. Polidochanol is such an agent. So it really does depend on what "main veins" means.I hope this helps.
Most insurance plans have specific exclusions for cosmetic procedures. Each plan may use different language, but the end result is the same. Unless you are having a lot of pain that interferes with your daily activities, your insurance plan will probably consider any treatment for varicose veins as cosmetic, and as such it will not be covered. It sounds as though you would not qualify for insurance reimbursement - regardless of how ugly they are.
Although it is generally safer and less allergenic, the fact that you had a life-threatening reaction suggests that you should not have either agent - ever. A good choice for you might be laser treatment of the feeding reticular veins - more painful and more treatments than with Polidocanol - or hyper tonic salt solution injected directly into the visible and offending spider veins. This will back fill the reticular vein feeders. I did this alone for years before I got and then abandoned a laser. Hypertonic saline has very small amounts of hydrochloric acid and small amounts of sodium hydroxide - neither of which causes allergic reactions. There is also a miniscule amount of aluminum that should not cause a problem. I now do a combination of Polidocanol for the feeding reticular veins and 23.4% salt solution for the spiders. The concentration of salt in the blood is only about 0.9%. The osmotic load with this concentration of hyper tonic saline is enormous and will usually destroy the reticular vein feeders - if they are not too big. Before I started using polidocanol, I used to get to them by filling the spiders and back filling the reticulars. Hypertonic saline is very safe to use, but by knocking out the feeders with polidochanol, the spiders will gradually fade away. This is my first choice because it has the least problems. Think twice before you let anyone inject anything that could kill you. Better yet, don't do it.
The most common complication of spider vein treatment is that the legs look worse before they look better. There can be bruising, scabs, and discoloration. All of these go away in a relatively short period of time. The next complication of spider vein treatment is that the treatment may not work. the usual cause of failure of therapy is that the doctor does not treat the underlying problem. Spider veins are dilated veins in the skin. In the legs they are caused by abnormal pressure relationships - usually malfunctioning venous valves in the larger veins up stream from the visible spiders. The next level of veins are called reticular veins. If they are not treated, there will almost certainly be either a recurrence or the development of another complication called telangectatic matting - a diffuse red discoloration caused be vessels too small to inject. With proper visualization these feeding reticular veins can be satisfactorily obliterated, thus preventing recurrence and matting. The worst complication is post treatment hyperpigmentation. This can be caused by blood that is trapped in the skin and leaves a pigment behind as it decomposes or by a darkening of the skin cause by minor injury to the skin in a process called post inflammatory hyperpigmentation. The first can occur in anyone and may or may not go away - it usually does. The second is more common in people with darker skin. There is always the possibility of temporary bruising, and depending on the agent used in sclerotherapy or the laser used there is the chance of skin necrosis - death of a small patch of skin. Since I stopped using lasers and started using polidochanol for reticular veins I have not seen skin necrosis. In the last 20 + years I have seen only 3 infections that required antibiotics. That's the list of complications. With careful attention to technique these can be kept to a minimum and the treatments can be very effective.
There are a variety of treatments for dilated spider veins on the face. None of them is permanent, so a good understanding of the cause of facial spider veins is a necessary first step in prevention of recurrence or even worsening of existing telangectasias. These facial spider veins are the consequence of the combination of genetic predisposition and long term sun damage. We can't control our genetics, but we do have influence over our environment. It helps to know the mechanism of injury: ultra violet light rays from the sun cause the development of free radicals in the skin. The free radicals 'steal' electrons from DNA molecules causing them to mutate. One of the mutations causes an increase in the enzyme that dissolves collagen in the skin. The blood vessels in the skin have collagen as their wall strength. They dilate up and can't get back down. So sun avoidance, sunscreen and a good topical antioxidant are required before the patient undertakes treatment. Removing them with out preventing future recurrence is a waste of time and money. The treatments that have been tried include Sclerotherapy (works by causing the vessel to clot. If the clot extends to the brain - not good.); Lasers like nd/Yag and KTP are effective but require multiple treatments and can be painful and cause bruising. IPL fades the spider veins over several treatments, but it is less painful and does not cause complications. After performing sclerotherapy and laser treatments on facial telangectaisas (spider veins) my personal preference is IPL. I think it has the best safety/efficacy profile of all the available treatments. The cost depends on the amount of skin that needs to be treated.