ENVENOMATION:STINGS

M.S.V.Sudeep

Pharm.D. [4th yr].

ENVENOMATIONDefinition:

The injection of a venom etc by means of a sting,etc.

STINGS:

Def : A pointed portion of a insect used for attack.

Order of insects belongs to stings are:

a)Hymenoptera- bees, wasps, hornets, fire ants.

b)Scorpionida- scorpions.

Vespids ↓

Apids ↓

Formicids ↓

Wasps Honey Bees Fire ants

Hornets,Yellow jackets. -

Jumper ants

1) ORDER HYMENOPTERA:Temperate regions.

It consists of - Are as follows:

Body of Honey bee - bright yellow with black triangular marking on abdomen.

They attract to Sweet & Meat.(10-15mm length of body).

Queen wasps- grow up to 20mm.

Inject venom- barbed- by bees -50mcg venom injected.

-smooth- by wasps.

Ants- Use jaws & then sting/spray- local irritating venom.

Some contain abdomen stingers-multiple stings.

VENOM:

It contains - a) Biogenic amines - Histamins,ACH.

- b) Enzymes - Phospholipase A, Hyalouronidase.

- c) Toxic peptides - Kinins,Mast cell degranulation- peptides,Apamin,etc.

High risk factors Lab diagnosis

Age 60yrs/ more. Intradermal test

Prolonged attack time. Positive venom skin test

High no. of stings Radio allegro absorbent test

Medical history include c.vascular problems.

CLINICAL FEATURES:

Clinical features TreatmentLocal reaction: Single sting-not allergic to

venom-mild effects,local pain.Local reaction:at vital location:mouth-aedama,airway obstruction.By wasps-severe cutaneous infection& cellulitis.

1. Remove stings use fingernails/blade but avoid foreceps.

2. Adrenaline(1:1000)near sting site.3. Papain-Relief psin.

4. Local application – 20%Aluminium sulfate.

5. Antihistamins-Diphenydramine(500mg).

6. Chlorphenaramine(4mg)7. LOCAL ANTISEPTIC CREAM8. Antibiotics for oinfections.

Allergic rxn – a)Anaphylaxis:

4% human population- hypesensitive to venom.Signs- tingling sensation,flushing,vomiting.

0.1% adrenaline Antihistamins Corticosteroids Cardiac monitoring.

b) Delayed rxn:

Urticarial,skin rash,pedal edema.Sometimes fever,rash,malasia.

1. Antihistamins,2. Analgesics,3. Haemodialysis- for renal failure.

Toxic rxn: Multiple stings -

vasodilation,

hypotension,fatigue,

dirrhoea,headache,

seizeures.

Delayed toxic rxn:

Haemodialysis,coagulopathy.

Parenteral antihistamins.

Large dose corticosteroids.

Bronchodilators.Haemodialysis.

PREVENTIVE MEASURES: Individual recovered from anaphylaxis from insect trained to self administer

adrenaline.

Wear tag for unconscious persons - after sting bite to discover them.

Destroy Hymnoptera nests I areas near to you.

Wear light coloured ,long sleeved,tight clothes.

Avoid bright /attractive colours,floral patterns.

Attractive scents,perfumes,soaps,shampoo- avoid in high risk area.

Take βblockers/Non steroidal analgesics.

Avoid ACE inhibiotors/calcium channel Antagonist. Immune therpy for - benefit from allergy.

2) ORDER SCORPIONIDA: It consists of 8legs cephalothorax,6 segmented tail,telson,sting,2 claws to

catch prey.

650 different species- into 6 families.

Most species- nocturnal& seek area that rae cool& moist. Straw yellow/ light browm/black colour.

India – red scorpion(Mesobuthus tamulus)-03 inches in length. Larger scorpions(Palamnaeus species)

7inches in length.

General rule- scorpions with thick & powerful claws- less toxic. Slender claws- more toxic. Scorpion sting- they do not bite.

Venom :

1. Most potent.

2. It contain phospholipase,Ach,Hyaluronidase,serotonin,Neurotoxins.

3. It causes - Gastro intestinal & Pulmonary haemorrhages.

Mode of Action:

Venom affects Na+ channels with pprolongation of Action Potentials.

Depolarisation of Nerves of both Adenergic & Parasympathetic system.

LOCAL SYSTEMIC

Rapidly developing local pain Autonomic stimulation

swelling mydriasis

redness Profuse sweating

lymphadenopathy urticaria

HTN

convulsions

Priapism,nausea.

CLINICAL FEATURES:

Lab tests:

1. ECG – Elevated T waves. Elevated ST segment.

Treatment:

Child over age of 5years – local application of ice for pain relief.

TREATMENT:1)During transport to hospital:

Immobilize, No transport, Local ice apply, -ve pressure suction device. No incision/suction.

2)On Arrival at Hospital: 1. Rep. failure- Mech. Ventilation.2. Pain- PCM/Morphine tabs.3. Allergy- Antihistamins.4. HTN- Nifidepine.5. Correct fluid & acid base imbalance.6. Hypotension- Dopamine(2-5mcg/kg/min)7. Convulsions- Diaxepam(5-10mg)8. Vomiting- metoclopramide.9. Antivenom therapy- scorpion antivenom- 1vial in 10 ml injection.

References:1. Modern Medical Toxicology –vv. Pillay ,4th Edition.Pg:157.

2. Hodgson, Ernest (2010). A Textbook of Modern Toxicology. John Wiley and Sons.

3. Berg, N; De Wever, B; Fuchs, H. W.; Gaca, M; Krul, C; Roggen, E. L. (2011).

4. "Toxicology in the 21st century--working our way towards a visionary reality". Toxicology in Vitro 25 (4): 874–81