I. Pain Puncturing the skin is the self-evident title of mesotherapy, so there will always be some pain caused by needle sticks. The intensity of the pain varies depending on the type of needle used, some are a little stronger, some are a little weaker. When we use mesotherapy in large doses (700 to 900 unit doses), we will probably inevitably change the injection needle several times during the treatment. When we use manual techniques, the injection needle should be inserted in a way that is quick and crisp without dragging. If needle insertion causes very intense pain, then we should withdraw the needle and stop the injection. The pH of the injection solution should be between 5 and 8 so as not to upset the physiological balance in the body. At the same time, we should regulate the viscosity and dosage of each unit of injection solution. Of course, the speed and depth of injection should never be neglected. When the acidity or alkalinity of the injection solution is too strong, it can be neutralized with sodium bicarbonate salt or ammonium chloride. It is best to be able to control the acidity or alkalinity of the injection solution close to pH 7.4. When the injected dose is not too large (1/20 cm3) and the speed of injection is fast at the true epidermal level, it is easy to experience pain. However, even when larger doses are used, it is possible not to cause pain if a slower perfusion method is used and/or if vertical mesodermal injections are used in the dermis. From an anatomical point of view, the main areas where injections are likely to cause pain are the inner muscles of the hands, feet, thighs and knees, and the neck, among others. Conversely, certain areas of the back, the head and certain areas of the face are largely painless. The practice of pulling, tugging and patting the skin distracts the candidate and proves to be a more practical approach. Female candidates will be more likely to experience pain during their menstrual period. It should be noted, however, that male candidates are usually less able to tolerate pain than female candidates. Erythema Erythema may occur during the mesotherapy procedure. Initially it may be a common erythema, but due to the use of certain AINE, it may develop into early skin gangrene or even lead to a very serious drug anaphylaxis. When PeridilHeparine is used, there is a possibility of very obvious localized erythema immediately. Acute drug anaphylaxis is a class I reaction to drugs in the GellandCoombs class. When acute drug anaphylaxis occurs, histamine is released in large amounts and enters the entire body circulation, causing high intensity vasodilation and a large reduction in venous blood return. This can lead to sudden death within minutes (as a direct result of global hypovolemia, cardiac insufficiency and acute spasm). When this reaction occurs, the patient will suddenly feel unwell, pale dramatically, and have irregular itching all over the body. Immediately afterwards, there is a risk of loss of consciousness, cessation of cardiopulmonary circulation, and asphyxia. From the pharmacological point of view, the only way to treat acute drug anaphylaxis is by injection of epinephrine Adrenalina (0.5 mg intramuscularly, or 1.0 mg diluted in 10 ml of saline and administered intravenously at a rate of 1 ml per minute, or in high doses diluted in intravenous adrenal corticosteroids until the amount of 1 g is injected in the first 4 h). The mesotherapy physician should have the following items and medications available at the time of diagnosis: ambú, Guédel cannula, oxygen cylinder and oxygen mask, adrenaline, adrenaline (adrenalina), lidocaine (lidocaina), etc. Overall, in mesotherapy it is most often the case that anaphylactic reactions are automatically confined to a local location, usually only to the skin area where the treatment is administered, and generally do not manifest symptoms of acute drug anaphylaxis. In principle, any drug can be considered to be allergenic. Procaine family as an allergenic drug has yet to be proven, although its molecular structure shows conditions under which an allergic reaction can occur. In any case, the potential of procaine to cause anaphylactic reactions is uncontroversial. Lutin (also known as rutin, rutosido) is associated with 27% erythematous reactions and pruritus when used in combination with herbaceous plants, such as yellow herbaceous mignonette (esberiven). The erythematous reaction and itching usually appear a few days after the administration of a course of treatment, although simply diluting the agent in saline is sufficient to eliminate this allergic reaction. Similar symptoms occasionally occur when an extract of artichoke (Chophytol) is used as an agent. The use of depolymerase can also produce a very itchy erythema, which generally depends on the dose used, although it can sometimes occur at normal doses. The erythema may also develop immediately (as if it were the result of a histamine reaction), or it may develop hours or even days later. When an allergic reaction occurs, it is accompanied by unbearable itching, which usually begins at night. The symptoms of the itchy area are redness, burning, sometimes raised, well-defined borders, and sometimes pain. In general, the allergic area will return to its original state, except in darker skin areas, where a light scar may remain. When an allergic reaction occurs, an anti-itch lotion (such as caladril lotion) containing calamine (calamina) can be used. Of course, the most prudent course of action in the event of an anaphylactic reaction is undoubtedly to discontinue the medication that caused the allergic reaction, although some authors of papers advocate the use of antihistamines systemically so that these enzymes can be reused. It is possible for some candidates to be allergic to metals, in which case we must increase the number of allergy tests and just use the needle alone without injections as a way to reduce the possibility of allergy to chromium and nickel. This is because the injections generally used in mesotherapy are made of these two metals. A different diagnosis is needed for rubella because it does not always come from an allergic reaction, but can be caused by a physical trauma, such as a needle stick can cause this reaction. The medical community generally believes that this type of rash or skin painting is likely to originate from vasodilatory kinins, which can justify the use of prophylactic antihistamines throughout the body. The use of antihistamines should not be administered only through the topical route, as this may lead to anaphylactic reactions on contact. Tip: Herbaceous rhinoceros (scientific name: Melilotusofficinalis (L.) Pall) is a biennial herb in the legume family, Herbaceae. It is distributed throughout northeastern, southern and southwestern China. It is distributed along the eastern coast of the Mediterranean in Europe, the Middle East, Central Asia, and East Asia. It is commonly cultivated in various provinces of China. The above-ground parts of herb are harvested for medicinal use. It is slightly sweet in taste, flat in nature, belongs to the spleen and large intestine meridian, has the effect of relieving cough, asthma, bronchitis, intestinal colic, trauma, lymph node swelling and pain.