Module on “Common cases of Keeta visha (Insect Bite) and their Ayurvedic management” by Dr. Shobha Bhat

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Common cases of Keeta visha found in Clinical practice

Human being is afraid of a multitude of dangers he has to encounter for his survival. These threats range from diseases of endogenous origin or exogenous factors like bites or stings of various animals.  Knowingly or unknowingly, human beings are subjected to the exposure of poisons or toxins. Poisoning cases due to insect bites are very common in clinical practice. People are often bitten by mosquitoes, flies, and spiders or stung by ants, bees, yellow jackets, wasps, hornets and scorpions. Although they are not usually serious, insect bites and stings can be itchy and painful and in some cases may need an emergency medical visit. Ayurveda explains in detail the signs and symptoms and treatment of different types of Keeta or insect bites.

It is estimated that between one and two million people in India are severely allergic to stinging insect venom. Each year 90 to 100 deaths from sting reactions are reported. More people die each year from the effects of insect venom than from snakebites. Exposure to most of these organisms usually causes cutaneous affections. Insect poisoning may cause injection of venom, physical trauma while burrowing the skin, sensitization reaction, both local & systemic, allergic reactions which include secondary infections, contact reactions to the secretions, reaction to retained mouth parts and transmission of infectious diseases.

Acharya Charaka has classified keeta to be of two types-Dooshivishaja and Pranahara. Sushruta has classified insects on basis of the doshic predominance as vataja – 18 types, pittaja or aagneya – 24 types, kaphaja or soumya – 13 types and sannipataja – 12 types. He has also mentioned keeta to be of two major types based on the potency of their visha as mandavisha keeta and teekshna visha keeta. Keeta found in clinical practice are either of Manda vishaja or Dooshi vishaja variety.

The largest phylum ‘Arthropoda’ consists 3 subphyla, comprising 9 classes. Class Insecta is the largest of the arthropod classes, containing hundreds of species. The common biting and stinging insects are explained in table 1.The characteristics produced by their bites or stings are explained in table 2.

Table.No.1

Common biting and stinging insects

Venomous (Stingers)

  • Bees
  • Wasps
  • Hornets
  • Yellow jackets
  • Fire ants
Non-venomous (Biters)

The differences are due to the nature of the bite or sting. Venomous insects attack as a defense mechanism, injecting painful, toxic venom through their stingers. Non-venomous insects bite and usually inject anti-coagulant saliva in order to feed on blood. Although local irritation and “allergic” reactions do occur from non-venomous bites, severe reactions such as anaphylactic shock usually only happen from venom stings.

Characteristics of Bites/Stings:

Table.No.2

Symptoms      Venomous Non-Venomous
Pain Always Uncommon
Redness Can be intense Mild or absent
Itching Sometimes Always
Swelling Can be intense Mild or absent
Allergic  reactions Common Rare

 

Local & Systemic Reactions:

Venomous stings are always very painful, red, and swollen up to 12 inches around the sting site. This is called a local reaction. In sensitive individuals, a systemic or “whole body” reaction occurs, with redness, hives (itchy raised skin lumps), and swelling far away from the sting site. These systemic reactions can progress to involve the airways and circulation and may be life- threatening. Obviously it is important to know the difference between local and systemic reactions so that affective treatment can be planned.

Different types of insects are described by various Ayurvedic texts under Keeta visha prakaraņa. These include description on the signs and symptoms and treatment of loota, vrishchika, makshika, mashaka, shatapadi, pipeelika, kanabha, etc.

Signs and symptoms of Makshika Visha:

Pidakas of blackish brown colour with instant exudation, Burning sensation, Fainting and fever, Itching, Swelling,  Pain etc have been explained as caused by makshika.

Bees are flying insects of the order Hymenoptera about 1.5 cm long, fairly hairy and brown with abdominal bands. There are over 16,000 described species, and possibly around 30,000 species in total. Hymenoptera are social creatures that typically sting to protect their colony, nest, or hive. At the rear end of bees, there is a sharp, pointed barbed stinger, which the bee will stick something with and release venom into its victim. The stinger can be thought of as a sort of syringe, sharp, hallow  tube. When a bee stings, it injects a venomous fluid under the skin. Only the honeybee leaves her stinger, with its venom sac attached in the skin of its victim. Since it takes two to three minutes for the venom sac to inject all its venom, instant removal of the stinger and sac usually reduces harmful effects.

Bee venom is a mixture of histamine, pheromones, enzymes, peptides, amino acids and other

acids, with 63 components in total. The main enzymes present are phospholipase A, hyaluronidase, and lecithinase; while the main peptides are mellitin, apamin and peptide 401.Bee venom is cytotoxic. Phospholipase A destroys cells by breaking up phospholipids, the main component of cell membranes. Lecithinase converts lecithine to lysolecithine ,which breaks down the membranes of blood cells. Hyaluronidase acts as a spreading factor, by breaking down hyaluronic acid, a polysaccharide interstitial fluid in connective tissue. Mellitin, a 26 amino acid peptide, acts to destroy blood cells by breaking up their membranes. It also lowers blood pressure, causes histamine release, and is the main pain-causing component. Both mellitin and apamin cause the body to release cortisol, a natural steroid, while peptide 401 is a powerful anti-inflammatory agent. The main amino acids in bee venom are cysteine and methionine, both of which contain sulphur which  induces cortisol release from the adrenal glands. Histamine causes itching and pain at the site of the sting.

When one is stung it is shortly followed by intense pain, swelling and reddening of the site where one was stung. In the centre of a bee sting you see a small black dot, which is the stinger. Reactions vary ranging from mild discomfort and swelling to an allergic reaction to bee venom, and some can die from a bee sting if they remain untreated for too long.

Signs and symptoms of Mashaka Visha:

Itching, Slight oedema at the site of bite, Mild pain and Redness is caused by bite by a fly or a mosquito.  Flies are of the order Diptera and can land on food and transmit bacteria to humans. They are thought to carry disease by transporting infectious agents on their feet. Biting flies attack humans to obtain a blood meal and can be very annoying. Biting flies of importance are sand flies, black flies, stable flies, horse flies and deer flies. They produce painful bites, swelling, itching and the area may remain red and itchy for several days or even longer.  Once a suitable host is located, a biting fly inserts its piercing mouthparts, lacerates the skin, then injects its anticoagulant-containing saliva to keep the blood flowing. In sensitive individuals, the fly’s saliva can trigger life-threatening allergic reactions.

Signs and symptoms of Shatapadi Visha:

Oedema at the site of bite, pain, burning sensation at the site of bite, sweating, redness and itching is caused by shatapadi visha. In severe conditions there is puss formation at the bite site.           Centipedes are fast-moving venomous, predatory terrestrial arthropods that have long bodies and many legs. They are slender, multisegmented arthropods with one pair of legs per segment and one pair of antennae. Their size may range from 1 to 30 cm, and coloration from bright yellow to brown-black. The first pair of legs has been modified into two sharp stinging structures connected to muscular venom glands. Approximately 3000 species of centipedes are found in the class Chilopoda, phylum Arthropoda. They prefer dark damp environments, such as under surfaces of rocks and logs, but on rainy days often retreat indoors. There have been a number of centipede envenomation cases reported worldwide describing a benign, albeit painful, syndrome.

Centipede venom is a pharmacologically diverse and potent substance. Venom can include

bioactive proteins, peptides, and other small molecules. These can have myotoxic, cardiotoxic, and neurotoxic effects. Currently, there are approximately 50 identified constituents of centipede  venom, all with different properties to block or activate ion channels.  Venom is produced by a gland at the base of the fangs and is administered by maxillipeds on the first body segment. Upon capturing prey, the poison gland is squeezed by the muscles surrounding it and ejects toxins through needle-like ducts. Despite this, the venom usually is not strong enough to be life threatening to people, and most centipede bites are typically more painful for humans than they are dangerous.

The most common scenario includes moderate to severe local symptoms associated with mild systemic symptoms. Local symptoms include pain, erythema, edema, lymphangitis/lymphadenitis, weakness, and paresthesias.    Skin necrosis may occur at the site of envenomation during the weeks following the sting, but rarely becomes extensive and heals spontaneously. Systemic symptoms may include anxiety, fever, dizziness, palpitations, and nausea.

Signs and symptoms of  Pipeelika  Visha:

Swelling, burning sensation and inflammation locally as after contact with fire, oedema in the surrounding region have been explained to be caused by pipeelika visha. Ants are tiny insects and their size varies from 3mm to 3 cm. They are physiologically distinguished mainly by having six legs, sharply elbowed antennae, and by having a bead-like pedicel formed from the first few abdominal segments. Some species have a powerful sting at the tip of the abdomen. In addition to the poisonous fluid that ants are able to spray at a distance of up to 10 cm (containing formic acid, alkaloids etc.), they use their mandible for biting.

The aqueous phase of fire ant venom contains four major allergenic proteins that are responsible for the specific IgE response of allergic animals.  In addition, the small protein fraction contains hyaluronidase and phospholipase. The piperidine alkaloids found in fire ant venom have local necrotic and hemolytic effects and are responsible for pain. Ant venom is a mixture of irritants and toxins , the main constituent of which is formic acid only in the case of subfamily Formicinae. Fire ant venom is made up of 95% water-insoluble alkaloid. The alkaloid portion consists primarily of 2,6 di-substituted piperidines, which have cytotoxic, hemolytic, antibacterial, and insecticidal properties.

Ant envenomation may be very serious even fatal in some individual cases. Fire ants are aggressive and will repeatedly sting anything that disturbs them. Characteristics of a sting include intense burning and itching which usually subsides within 1 hour. However, the itching may return periodically over the next several days or more. Within the next 4 hours, a blister forms at the site of a sting. A white pustule forms in a day or so. Treatment is aimed at preventing secondary bacterial infection, which occurs easily if the pustule is scratched or broken. On rare occasions, anaphylaxis, or a generalized, systemic allergic reaction to the fire ant stings, can occur. This is usually in persons who have been sensitized by previous stings. Symptoms include flushing, general hives, swelling of the face, eyes or throat, chest pains, nausea, severe sweating, loss of breath or slurred speech. Some people are allergic to the sting and in rare cases, can die.

Signs and symptoms of  Kanabha  Visha:

Severe pain, swelling, aching and heaviness of the body, blackish discolouration locally, herpes

fever and vomiting are supposed to be caused by kanabha visha. Stinging is an excellent defense in wasp colonies against predators and other possible dangers which present a threat to the nests and their occupants. A stinger is actually a modified egg-laying tube, which is connected to a venom sac inside the insect’s body. Chemicals in the venom cause the pain and irritation from the sting.

As a wasp which includes yellow jackets, hornets, paper wasps or mud dauber stings, an alarm pheromone is released in the venom signaling nearby coworkers to deliver stings to the same area on the body. Wasp venom components are generally categorized as high molecular weight proteins that includes phospholipases, hyaluronidases, antigen 5 etc., Low molecular weight peptides that includes mastoparans, wasp kinins and chemotactic peptides, Bioactive molecules such as histamine, serotonin, catecholamines, acetylcholine, tyramine etc.

Reactions to stings vary depending on the number of stings delivered and body’s reaction to the venom in the sting. Normal reactions are characterized by a painful, reddened swollen area that may also itch, but dissipates within minutes. More serious local reactions last for days. The pain, swelling and itching will be more intense in the area directly surrounding the sting site. The most serious reaction is a systemic allergic reaction known as anaphylaxis. This type of reaction generally occurs rapidly after the sting and affects the whole body. A person may feel dizzy, nauseated and weak, experience stomach cramps and diarrhea. Also coughing, itching around the eyes, hives, wheezing, difficulty breathing or swallowing, vomiting, low blood pressure, shock, unconsciousness, darkened skin and death can occur in highly sensitive people.

Keetavisha chikitsa

The main aim of treatment in all the above said varieties of Keetas is to give relief the pain, to avoid further complications, treatment for the poison, treatment for the symptoms and psychological approach. Medicines used in day to day practice include Dashanga Gutika, Vilwadi gutika,  Visha vilwadi gutika,  Dooshivishari gutika,  Amritottara Kashaya, Punarnavadi kashaya, Guloochyadi kashaya, Patola katurohinyadi kashaya etc.External modalities include lepa, seka or avagaha with the following drugs depending on the dosic predominance like Vilwadi gutika (Kapha vataghna), Shigru punarnavadi yoga(Kapha-vata), Haridra (Kapha- vata), Shatadhauta Ghrita ( Pittaghna), Rakta chandana ( Pittaghna), Nalpamaradi yoga( Kapha-pittaghna), Kottamtagaradi yoga( Tridoshagna) and Vara choorna ( Tridoshagna.)

Vrishchika Visha:

A scorpion is an invertebrate animal with eight legs belonging to the order Scorpiones in the class Arachnida. Out of 1500 scorpion species, 50 are dangerous to humans. Almost all of these lethal scorpions, except the Hemiscorpius species, belong to the scorpion family called the Buthidae, the lethal members of the Buthidae family include the genera of Buthus, Parabuthus, Mesobuthus, Tityus, Leiurus, Androctonus, and Centruroides. Scorpions use their pincers to grasp their prey; then, they arch their tail over their body to drive their stinger into the prey to inject their venom, sometimes more than once.The scorpion can voluntarily regulate how much venom to inject with each sting.

All species of scorpion possess venom. Scorpion venom is a water-soluble, antigenic, heterogenous mixture. The venom is composed of varying concentrations of neurotoxin, cardiotoxin, nephrotoxin, hemolytic toxin, phosphodiesterases, phospholipases, hyaluronidases, histamine, serotonin, tryptophan, and cytokine releasers. The most potent toxin is the neurotoxin.

Signs and symptoms:

The signs of the envenomation are determined by the scorpion species, venom composition, and

the victim’s physiological reaction to the venom. The signs occur within a few minutes after the sting and usually progress to a maximum severity within 5 hours. Local evidence of a sting may be minimal or absent in as many as 50% of cases of neurotoxic scorpion stings. A sharp burning pain sensation at the sting site, followed by pruritus, erythema, local tissue swelling, and ascending hyperesthesia, may be reported. A macule or papule appears initially at the sting site, occurring within the first hour of the sting, progresses to a purpuric plague that will necrose and ulcerate. Pain, erythema, induration, and wheal may be present. These are secondary to venom activation of kinins and slow-releasing substances. Most of the symptoms are due to either the release of catecholamine from the adrenal glands (sympathetic nerves) or the release of acetylcholine from postganglionic parasympathetic neurons. Thalamus-induced systemic paresthesia occurs in all 4 limbs. Patients experience venom-induced cerebral thrombosis strokes. The level of consciousness is altered, especially with restlessness, confusion, or delirium. Patients have abnormal behavior. Intense local burning pain with minimal swelling at sting site, followed by ascending numbness and tingling, then paralysis and convulsions Hypertension secondary to catecholamine and renin stimulation, observed as early as within 4 minutes after the sting and lasts a few hours. Hypotension – Less common and occurs secondary to excess acetylcholamine or catecholamine depletion.Tachycardia is greater than 130 beats per minute, although bradycardia can be observed. Cardiovascular collapse occurs secondary to biventricular dysfunction and profuse loss of fluids from sweating, vomiting, diarrhea, and hyper salivation. Respiratory failure may occur secondary to diaphragm paralysis.

Neelithulasyadi  kashaya ,Lodrasevyadi  kashaya, Patola- katurohinyadi kashaya,

Guloochyadi kashaya, Vilwadi gutika , Gopeechandanadi gutika,  Dashanga gutika , Neelidaladi ghritha etc. are the drug of choice in such conditions. Lepa, Seka, Avagaha etc. with Lodrasevyadi Yoga, Neelithulasyadi Yoga, Thriphaladi Choorna, Nalpamaradi Choorna etc may be considered.

  1. Describe the classification of Keeta Visha as described by our Acharyas.

Acharya Charaka has classified keeta to be of two types-Dooshivishaja and Pranahara. Sushruta has classified insects on basis of the doshic predominance as vataja – 18 types, pittaja or aagneya – 24 types, kaphaja or soumya – 13 types and sannipataja – 12 types. He has also mentioned keeta to be of two major types based on the potency of their visha as mandavisha keeta and teekshna visha keeta.

  1. Name some venomous stingers which are commonly encountered.

Bees, Wasps, Hornets, Yellow jackets, Fire ants and scorpios are some of the commonly encountered venomous stingers. All of these possess a sting through which they harm the humans.

  1. What are the components of a bee venom?

Bee venom is a mixture of histamine, pheromones, enzymes, peptides, amino acids and other acids, with 63 components in total. The main enzymes present are phospholipase A, hyaluronidase, and lecithinase; while the main peptides are mellitin, apamin and peptide 401.Bee venom is cytotoxic.

  1. How does a bee venom act on the body?

Phospholipase A destroys cells by breaking up phospholipids, the main component of cell membranes. Lecithinase converts lecithine to lysolecithine ,which breaks down the membranes of blood cells. Hyaluronidase acts as a spreading factor, by breaking down hyaluronic acid, a polysaccharide interstitial fluid in connective tissue. Mellitin, a 26 amino acid peptide, acts to destroy blood cells by breaking up their membranes. It also lowers blood pressure, causes histamine release, and is the main pain-causing component. Both mellitin and apamin cause the body to release cortisol, a natural steroid, while peptide 401 is a powerful anti-inflammatory agent. The main amino acids in bee venom are cysteine and methionine, both of which contain sulphur which  induces cortisol release from the adrenal glands. Histamine causes itching and pain at the site of the sting.

  1. Name some important biting flies.

Biting flies of importance are sand flies, black flies, stable flies, horse flies and deer flies. They produce painful bites, swelling, itching and the area may remain red and itchy for several days or even longer.  Once a suitable host is located, a biting fly inserts its piercing mouthparts, lacerates the skin, then injects its anticoagulant-containing saliva to keep the blood flowing. In sensitive individuals, the fly’s saliva can trigger life-threatening allergic reactions.

  1. Describe in brief about Shatapadi Visha

Oedema at the site of bite, pain, burning sensation at the site of bite, sweating, redness and itching is caused by shatapadi visha. In severe conditions there is puss formation at the bite site. Centipede venom is a pharmacologically diverse and potent substance. Venom can include bioactive proteins, peptides, and other small molecules. These can have myotoxic, cardiotoxic, and neurotoxic effects. The most common scenario includes moderate to severe local symptoms associated with mild systemic symptoms. Local symptoms include pain, erythema, edema, lymphangitis/lymphadenitis, weakness, and paresthesias.    Skin necrosis may occur at the site of envenomation during the weeks following the sting, but rarely becomes extensive and heals spontaneously. Systemic symptoms may include anxiety, fever, dizziness, palpitations, and nausea.

  1. What causes the signs and symptoms in an ant bite or sting?

Swelling, burning sensation and inflammation locally as after contact with fire, oedema in the surrounding region have been explained to be caused by pipeelika visha. The aqueous phase of fire ant venom contains four major allergenic proteins that are responsible for the specific IgE response of allergic animals.  In addition, the small protein fraction contains hyaluronidase and phospholipase. The piperidine alkaloids found in fire ant venom have local necrotic and hemolytic effects and are responsible for pain. Ant venom is a mixture of irritants and toxins , the main constituent of which is formic acid only in the case of subfamily Formicinae. The alkaloid portion consists primarily of 2,6 di-substituted piperidines, which have cytotoxic, hemolytic, antibacterial, and insecticidal properties.

  1. Describe in brief about the wasp venom.

Wasp venom components are generally categorized as high molecular weight proteins that includes phospholipases, hyaluronidases, antigen 5 etc., Low molecular weight peptides that includes mastoparans, wasp kinins and chemotactic peptides, Bioactive molecules such as histamine, serotonin, catecholamines, acetylcholine, tyramine etc.

  1. Name some Agada used in the treatment of Keeta Visha

Medicines used in the management of Keeta Visha include Dashanga Gutika, Vilwadi gutika,  Visha vilwadi gutika,  Dooshivishari gutika,  Amritottara Kashaya, Punarnavadi kashaya, Guloochyadi kashaya, Patola katurohinyadi kashaya etc. External modalities include lepa, seka or avagaha with the following drugs depending on the dosic predominance like Vilwadi gutika (Kapha vataghna), Shigru punarnavadi yoga(Kapha-vata), Haridra (Kapha- vata), Shatadhauta Ghrita ( Pittaghna), Rakta chandana (Pittaghna), Nalpamaradi yoga( Kapha-pittaghna), Kottamtagaradi yoga( Tridoshagna) and Vara choorna ( Tridoshagna.)

  1. Name some Agada specific for loota Visha.

Neelithulasyadi  kashaya ,Lodrasevyadi  kashaya, Patola- katurohinyadi kashaya, Guloochyadi kashaya, Vilwadi gutika , Gopeechandanadi gutika,  Dashanga gutika , Neelidaladi ghritha etc. are the drug of choice in Loota Visha. Lepa, Seka, Avagaha etc. with Lodrasevyadi Yoga, Neelithulasyadi Yoga, Thriphaladi Choorna, Nalpamaradi Choorna etc may be considered.

References:

  1. Zhi-Hong Jiang et al, Bicyclic Polyketide Lactones from Chinese Medicinal Ants, Journal of Natural Products 3(1) (2008) 13-4.
  2. AyurvedaDipika, Commentary on Charaka Samhita. Chikitsasthana. 23/140, 5th Ed. (Munshiram Manoharalal Publishers Pvt. Ltd, New Delhi), 1992,456
  3. Commentary on Sushruta Samhita, kalpasthana.8/4,Vaidya Yadavji Trikamji Acharya, 6th Ed. Varanasi:Chaukhambha Sanskrit Sansthan; 1997.p.577.
  4. Commentary on Sushruta Samhita, kalpasthana.8/22,Vaidya Yadavji Trikamji Acharya, 6th Ed. Varanasi:Chaukhambha Sanskrit Sansthan; 1997.p.581.
  5. Aldo Castellani & Albert J. Chalmers, Manual of Tropical Medicine, 3rd (Bailliere, Tindall & Cox London), 1919. 453.
  6. Langley RL. Animal-related fatalities in the United States-an update. Wilderness Environ Med, 16(2) (2005) 67-74.
  7. Balit CR, Harvey MS, Waldock JM, Isbister GK. Prospective study of insect bites in Australia. J Toxicol Clin Toxicol. 42(1) (2004) 41-8.
  8. AyurvedaDipika, Commentary on Charaka Samhita. Chikitsasthana. 23/157,5th Ed. New Delhi: Munshiram Manoharalal Publishers Pvt. Ltd;1992.p.496.
  9. Commentary on Sushruta Samhita, kalpasthana.8/36,Vaidya Yadavji Trikamji Acharya, 6th Ed. Varanasi:Chaukhambha Sanskrit Sansthan; 1997.p.602.
  10. Vagbhata, Ashtang Hridaya,Sarvaangasundara & Ayurveda Rasaayana,Uttaratantra.37/65, Collated by Anna Moreshwara Kunte, 9th Ed.Varanasi:Chaukhamba Orientalia Publication;2002.p. 678.
  11. AyurvedaDipika, Commentary on Charaka Samhita. Chikitsasthana. 23/162,5th Ed. New Delhi: Munshiram Manoharalal Publishers Pvt. Ltd;1992.p.502.
  12. Commentary on Sushruta Samhita, kalpasthana.8/38,Vaidya Yadavji Trikamji Acharya, 6th Ed. Varanasi:Chaukhambha Sanskrit Sansthan; 1997.p.603.
  13. Commentary on Sushruta Samhita, kalpasthana.8/30,Vaidya Yadavji Trikamji Acharya, 6th Ed. Varanasi:Chaukhambha Sanskrit Sansthan; 1997.p.600.
  14. AyurvedaDipika, Commentary on Charaka Samhita. Chikitsasthana. 23/156,5th Ed. New Delhi: Munshiram Manoharalal Publishers Pvt. Ltd;1992.p.499.
  15. Vagbhata , Ashtanga Samgraha- Indu vyakhya.Uttaratantra.43/22, New Delhi: Central Council for Research in Ayurveda and Siddha;1991.p.532.
  16. Bush SP, King BO, Norris RL, Stockwell SA. Centipede envenomation. Wilderness Environ Med. 12(2) (2001) 93-9.
  17. Commentary on Sushruta Samhita, kalpasthana.8/34,Vaidya Yadavji Trikamji Acharya, 6th Ed. Varanasi:Chaukhambha Sanskrit Sansthan; 1997.p.601.
  18. Junping Kou, et al, Analgesic and Anti-inflammatory Activities of Chinese Medicinal Ants,  Biological and Pharmaceutical Bulletin, 3(1) (2010) 23-4.
  19. Commentary on Sushruta Samhita, kalpasthana.8/27,Vaidya Yadavji Trikamji Acharya, 6th Ed. Varanasi:Chaukhambha Sanskrit Sansthan; 1997.p.606.
  20. AyurvedaDipika, Commentary on Charaka Samhita. Chikitsasthana. 23/152,5th Ed. New Delhi: Munshiram Manoharalal Publishers Pvt. Ltd;1992.p.503.
  21. Peters S. A Colour Atlas of Arthropods in Clinical Medicine. (Wolfe Pub Ltd) 1992, 1-304.

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