Jellyfish (usually large jellyfish, including species of the genus Jellyfish) are toxic marine organisms with a large number of stinging cells on their tentacles, which contain venom. When the human body touches the jellyfish tentacles, the stinging cells can pierce the skin, causing stinging cell dermatitis, and also allergic-like reactions and shock, which can lead to death in serious cases. The actual fact that the jellyfish is transparent in the seawater makes it difficult for swimmers to identify it, so it is easy to get stung by the jellyfish. The early treatment of jellyfish stings, especially the early treatment of anaphylaxis, is important to reduce the death rate. The clinical manifestations of jellyfish stings Mild jellyfish stings only show local symptoms, while severe stings can cause systemic allergic reactions or toxic shock, and even death in severe cases. The local symptoms are burning, itching, and stinging sensations immediately after the sting, and the local erythema and papules gradually appear in a linear arrangement, and the marks are mostly in the same direction as the tentacles, as if they were whip marks, and itching is obvious. The most important thing is that you can get a good idea of what you are looking for. Local symptoms generally last 10 to 20 d, and in some cases up to several months, and in severe cases there may be hyperpigmentation, scar formation, and gangrene. Systemic symptoms: Allergic reactions occur within minutes to hours after severe stings and are mainly manifested in the following areas. Skin and mucosal changes: Patients initially feel tightness in the chest and itchy skin, followed by urticaria and angioneurotic edema, mainly around the eyes and upper and lower lips, and occasionally involving the throat, which is life-threatening. Whistling system: Patients present with acute pulmonary edema manifestations such as cough, chest tightness, shortness of breath, dyspnea, coughing up large amounts of foamy sputum, and also acute whistling distress syndrome; dyspnea can be quite severe, often accompanied by cough, asthma and cyanosis, leading to whistling circulatory failure, which is a common cause of death. Neurological system: headache, cold or heat sensation, vertigo, movement disorders, spastic or flaccid paralysis, delirium, etc. Circulatory system: arrhythmias, bradycardia, hypotension and heart failure, etc. Motor system: manifested as diffuse myalgia, arthralgia, back pain, muscle spasm and rectus abdominis muscle ankylosis, etc. Uterine muscle contraction may cause lower abdominal pain. Digestive system: manifesting as nausea, vomiting, diarrhea, difficulty in swallowing and increased saliva secretion, etc.; abdominal colic with vomiting and diarrhea may occur due to contraction of intestinal smooth muscle. Other: hemolysis, hepatic and renal impairment, conjunctivitis, bulbar conjunctival edema, corneal ulceration, lacrimation, etc. Anaphylaxis can occur suddenly after a jellyfish sting, even within a few minutes, and is often characterized by a sense of near death followed by manifestations in one or more target organs (cardiovascular, inhalation, skin, or gastrointestinal tract). If the cardiovascular system is the main target organ, the reaction is particularly rapid and dangerous, with syncope and shock occurring within minutes or even a minute, with the skin changing from pale to cyanotic and death occurring within a short time. Features of anaphylaxis: The main feature is the manifestation of shock, i.e., the blood pressure drops sharply to <80/50 mmHg and the patient develops varying degrees of impaired consciousness. Secondly, the appearance of shock is often preceded or accompanied by allergy-related symptoms: ① Skin mucosal manifestations: often the earliest and most frequent signs of anaphylaxis, including skin flushing, pruritus, followed by widespread urticaria and/or angioneurotic edema, but also sneezing, watery nasal discharge, hoarseness, and even affect whistling. ② Symptoms of obstruction of the whistle: It is the most common manifestation of the syndrome and the most important cause of death. Due to airway edema, increased secretions, and laryngeal and/or bronchospasm, patients develop a feeling of laryngeal obstruction, chest tightness, shortness of breath, wheezing, breath-holding, and cyanosis, resulting in death due to asphyxia. (iii) Circulatory failure manifestations: Patients first have palpitations, sweating, pallor, rapid and weak pulse; then develop into cold limbs, cyanosis, rapid drop in blood pressure, disappearance of pulse, or even failure to measure blood pressure, which eventually leads to cardiac arrest; a small number of patients with pre-existing coronary arteriosclerosis can be complicated by myocardial infarction. ④Altered consciousness: Patients often first experience fear, irritability and dizziness; as cerebral hypoxia and cerebral edema increase, confusion or complete loss of consciousness may occur, and convulsions and limb tonicity may also occur. Irukandji syndrome refers to the reaction to a jellyfish sting, including headache, sweating, nausea, severe pain in several parts of the body, cramps in the limbs, burning sensation in the face, tachycardia, and increased blood pressure. Delayed jellyfish sting syndrome is the impairment of multiple organ functions that occurs between 2 and 48 h after jellyfish sting, except for cardiovascular toxicity manifestations, mainly liver and kidney function impairment, which may be related to the large dose of toxin from jellyfish sting. The experimental study showed that rats were given smaller doses of toxin (90 μg/kg) with only mild hepatic and renal impairment, and multiple organ function impairment could occur when the amount of toxin was increased to 180 μg/kg; then increased to 360 μg/kg, severe multiple organ function impairment occurred, and delayed-onset sea sting syndrome was mostly poisoned by this dose; when the amount of toxin was increased to 540 μg/kg, the animals died within 10 h. The animal died within 10 h. Diagnosis and classification Diagnostic points The patient has a clear history of sea sting injury, and the diagnosis can be made based on the medical history and clinical manifestations. If a systemic reaction occurs immediately after a jellyfish sting and is difficult to explain by other diseases, the possibility of this disease should be considered immediately, so the diagnosis is generally not very difficult. The diagnosis of anaphylaxis after a jellyfish sting should be taken more seriously clinically, as it occurs very quickly and must be diagnosed and treated immediately, otherwise it is life-threatening. The diagnosis of anaphylaxis is generally confirmed by the occurrence of a systemic allergic reaction involving several systems with signs of shock a few minutes after a jellyfish sting. If the history of the sting is unclear, an optical magnification examination of the wound may be considered to look for the stinging capsule of the jellyfish and to differentiate it from the following diseases. The most common cause of vagal syncope (or vagal deficiency) is the weakness of the patient, especially if the patient is febrile, dehydrated or hypoglycemic. Patients often present with pallor, nausea, and cold sweats, which may be followed by syncope and easily misdiagnosed as anaphylaxis. However, there is no pruritus or rash, the syncope improves immediately after lying down, and the blood pressure is low but the pulse is slow, which is different from anaphylaxis. Vagal vasovagal syncope can be treated with atropine-like drugs. Hereditary angioedema: It is a disease of autosomal inheritance that lacks complement C1 esterase inhibitors. Patients can develop suddenly under the stimulation of some non-specific factors (e.g. infection, trauma, etc.) and manifest as angioedema of the skin and mucous membranes of the whistle; due to airway obstruction, patients also often have wheezing, shortness of breath and extreme inspiratory distress, which is quite similar to anaphylaxis. However, the onset of the disease is slow, and many patients have a family history or a history of seizures since childhood, and there is usually no drop in blood pressure or urticaria at the onset of the disease. The most important thing is to make sure that you have a good understanding of the situation. The patient only has local skin reactions, which can cause itching and burning sensation. The patient may have a local skin reaction and a systemic allergic reaction, but does not have the symptoms of a heavy case. In addition to the local skin reaction, the patient may have a systemic allergic reaction, but does not have the symptoms of a heavy case, or may have one of the following conditions: (1) an allergic person; (2) an age of 65 years; or (3) a history of cardiovascular disease. In this type of patients, the sting can develop into a heavy case if the area of the sting is large. In addition to the local skin reaction, the patient can be diagnosed as a heavy jellyfish sting if there is any functional damage to the lungs, circulation, nerves, kidneys and coagulation system. A few patients develop rapidly, with acute pulmonary edema and anaphylaxis occurring within 10 minutes to 6 h. In severe cases, sudden death is required, so early identification of heavy patients is necessary. Clinical patients with one of the following conditions must be closely observed: ① allergic; ② large skin injury, skin reactions are more serious; ③ axillary temperature ≥ 38 ℃; ④ whistling system symptoms, such as chest tightness, shortness of breath, inspiratory difficulties, oxygen saturation ≤ 95%; ⑤ cardiac arrhythmia or blood pressure drop; ⑥ irritability, confusion; ⑦ nausea, vomiting. The patient's vital signs, especially the patient's mental, inspiratory and circulatory status, should be observed and evaluated; anaphylactic shock should be identified as early as possible and various life-threatening signs should be detected, and effective life support should be provided in a timely manner. Local treatment Immediately after contact with the jellyfish, go ashore and flush the sting with seawater, remember not to flush with fresh water because the osmotic pressure of fresh water is low and can cause the stinging capsule to burst and release toxins; rescuers should wear gloves to avoid being stung themselves. Patients should go to the hospital as soon as possible, rinse with 5% to 10% sodium bicarbonate (or saturated alum solution), and wet compress the affected area with sodium bicarbonate solution for >30 min each time, several times a day; also use topical application of glycopyrrolate lotion or local application of glucocorticoid ointment, etc.; those with clear wounds should also consider injecting tetanus antitoxin. The use of vinegar (acetic acid) to treat jellyfish stings to relieve pain is common, but the effect of acetic acid on jellyfish tentacle filament sac emission is related to its concentration and jellyfish species, and there is evidence to suggest that most species of jellyfish stings can cause increased pain or filament sac emission. Anti-allergic treatment Patients with jellyfish stings can choose anti-allergic medications depending on the situation. There are dozens of antiallergic drugs commonly used clinically, and the common preparations are loratadine, cetirizine, imipramine, and astemizole. Symptomatic treatment Pain: analgesic treatment such as morphine and dulcolax can be given when the pain is severe. Elderly patients and patients with whistling system diseases need to pay attention to the adverse effects of whistling inhibition; those with severe myospasm can be given symptomatic treatment with sedative drugs such as diazepam. Arrhythmia control: attention should be paid to finding the cause of arrhythmia, targeted treatment according to pathophysiology, monitoring the QT interval of electrocardiogram, prevention and identification of tip-twist ventricular tachycardia. Hypotension: should be treated according to different pathophysiology, those with insufficient volume should be immediately and rapidly rehydrated, those due to allergic factors should choose intra-muscular injection, subcutaneous injection or IV epinephrine; those with poor effect of antihypertensive drugs need to exclude peripheral vascular paralysis and stress cardiomyopathy. Bronchospasm and inspiratory difficulties: epinephrine, glucocorticoids, and bronchodilators should be considered, as well as mask administration of oxygen or tracheal intubation for mechanical ventilation to relieve symptoms. It should be emphasized that acute laryngeal edema should be detected and identified in a timely manner, and 1:1 000 epinephrine 0.2 to 0.5 mL should be given intramuscularly rapidly, or mannitol can be administered rapidly and quietly to relieve symptoms; in cases of severe airway obstruction and in out-of-hospital emergencies, on-site cricothyrotomy, or tracheal intubation and percutaneous tracheotomy can be considered to rapidly relieve airway obstruction. Acute pulmonary edema: In acute allergic pulmonary edema, based on the application of anti-allergic treatment such as epinephrine and glucocorticoids, the application of anticholinergic drugs such as scopolamine hydrobromide or atropine can be considered to reduce pulmonary exudation; attention should also be paid to the early recognition and correct management of internal asphyxia (large amounts of foamy sputum filling the lungs, resulting in a manifestation similar to asphyxia with ventilation impairment as the main cause), timely tracheal intubation and end-whistle If a large amount of blood and water gushes out from the tracheal tube, capillary leak syndrome should be excluded, and albumin should be used with caution. Cardiogenic can consider oxygen, intravenous morphine, furosemide, cetiran and vasodilators and other drugs. Anaphylaxis: The treatment of anaphylaxis after dealing with jellyfish stings must be decisive and active without losing time. The key to resuscitation is to carry out all necessary measures as early as possible and as soon as possible, and it is also important to be flexible. Quickly stop entering and move out of the sting environment, the patient must lie flat so that the head is in a low position, and pay attention to keeping the airway open for whistling. Immediately inject 1:1,000 epinephrine 0.2 to 0.5 mL or 0.02 to 0.03 mL/(kg-session) subcutaneously or intramuscularly. The safety of intramuscular injection of epinephrine is well established, and physicians are encouraged to use intramuscular injection. If symptoms do not improve within 5 min of injection or if the condition worsens, the drug may be repeated. Routine intravenous administration of 1 mg epinephrine is contraindicated in the resuscitation of non-cardiac arrest patients with this condition and severe asthma; intravenous infusion of an appropriately concentrated solution (1/10,000 or less, but never 1/1,000) may be used in patients in immediate life-threatening severe shock, but should be done at the discretion of an experienced physician and under ECG monitoring. Epinephrine self-administration devices may be used at the scene of an emergency. Epinephrine can make the bronchospasm fast diastolic through β receptor effect, and make the peripheral small blood vessel contraction through α receptor effect, and also can counteract the release of some type I allergic reaction mediators, which is the drug of choice for the rescue of anaphylaxis, and most patients can gradually recover from shock symptoms within half an hour; on the contrary, if the shock continues not to improve, intravenous dexamethasone 10～20 mg, or hydrocortisone succinate 200～400 mg should be injected early. If the shock does not improve, dexamethasone 10～20 mg or hydrocortisone succinate 200～400 mg should be injected intravenously as soon as possible. Emphasize the early administration of sufficient intravenous fluids, the first dose of rehydration 500 mL can be rapidly dripped, the first day of rehydration in adults can generally be up to 4 000 mL, can choose to infuse crystal or colloidal solution, advocate priority to choose to infuse crystal solution. If the sting is not long away, it is estimated that the venom has not yet spread completely, the proximal end of the stabbed limb should be tightly bound with a tourniquet as soon as possible to slow down the absorption and limit the rate of harmful venom diffusion, or the sting can be considered locally closed with 0.005 percent epinephrine 2-5 mL injection, but this method can cause necrosis of the terminal limb, so closed injection of the distal limb should be used with caution. Note: In case of dyspnea or cyanosis, oxygen therapy can be given as soon as possible and artificial ventilation can be performed if necessary. Some patients present with acute severe bronchial asthma or laryngeal edema and need to be recognized. Drugs such as beta-blockers may aggravate the post-sting reaction if they are being taken and are resistant to epinephrine therapy. Due to the state of anaphylaxis, the patient’s allergy threshold is very low, which may turn some drugs that were not originally allergic into allergens, so it is important not to use too much or too many drugs. The most important thing to emphasize is that glucocorticoids are slow to take effect, so when rescuing anaphylactic shock caused by jellyfish stings, you can’t rely only on this type of drug. The other: the combination of acute progressive liver and kidney and other vital organ failure. The following measures should be taken to avoid jellyfish stings: ① Clear safety warnings should be set up at beachside swimming places or troop sea training sites. The first thing you need to do is to make sure that you have a good idea of what you are getting into. The jellyfish tend to be freshwater creatures, and when it rains, the jellyfish will automatically move closer to the sea, so avoid swimming in the sea after the rain. ④Before entering the sea for swimming and training, you should do a good job of scientific propaganda to prevent harm in order to improve the knowledge and ability of self-protection. ⑤ Interception facilities (such as shark-proof nets and shark moss interception nets) should be set up in beach swimming areas or training places, which can intercept about 80% of harmful jellyfish. Even if the jellyfish is dead, as long as its stinging capsule is still wet, it may sting people, and the jellyfish pieces floating on the beach should not be touched or picked up by hand. The first thing you need to do is to bring a protective tool and not to touch the jellyfish directly. If possible, apply a protective agent for jellyfish stings.