Insect bites and stings

Breadfruit

Artocarpus altilis

Dried male flower clusters are burned throughout Oceania to keep mosquitoes away. In laboratory biting-deterrent tests on Aedes aegypti, fatty acids from the flowers (capric, undecanoic and lauric acid) deterred biting more than DEET; protection in real-world use has not been measured.

Catnip

Nepeta cataria

Nepetalactone, the main component of catnip oil, repels mosquitoes in laboratory tests by activating the insect irritant receptor TRPA1 (it does not activate the human receptor). It was a better spatial repellent than DEET but a weaker contact repellent.

Sangre de grado

Croton lechleri

Sap preparations applied to the skin relieved itching, pain and swelling of insect bites in clinical studies summarised in a 2003 review; details and trial quality are not given in the abstract.

Sweetgrass

Anthoxanthum nitens

The Flathead burned it as incense to 'keep the bugs away'. In a laboratory feeding bioassay, extracts deterred biting by Aedes aegypti mosquitoes, and phytol and coumarin were identified as the active compounds. Not tested on people.

Zedoary

Curcuma zedoaria

A water-balm with 15% zedoary essential oil repelled Aedes aegypti mosquitoes in arm-in-cage tests (median complete protection 150 minutes) and caused no irritation in 12 volunteers' patch tests.

Annatto

Bixa orellana

Seed paste is applied to the skin by forest peoples to repel mosquitoes and in Brazil, Cuba and Paraguay as an insect repellent; repellent action against sandflies has been shown experimentally.

Arnica

Arnica montana

Inflammation from insect bites was among the external uses in the German Commission E (1984) and WHO monographs, as recorded in the EMA assessment; EMA did not adopt this indication.

Balm of Gilead

Commiphora gileadensis

Used in Saudi Arabia as an antidote to scorpion stings.

Burn jelly plant

Bulbine frutescens

Zulu and Afrikaans folk use for insect bites.

Cajuput

Melaleuca cajuputi

A common south-east Asian household remedy for insect bites.

Chong lou

Paris polyphylla

Listed in the Chinese Pharmacopoeia for venomous snake bites and used in Nepal as an antidote to poisonous insects and snakes; untested clinically.

Curry leaf

Murraya koenigii

In Ayurveda, a paste of curry leaves and buttermilk (Kaidaryayuktatakra lepa) is applied to scorpion stings, and juice of the leaves, bark and root is taken by mouth. There are no clinical studies; a scorpion sting can be a medical emergency.

Ethiopian frankincense

Boswellia papyrifera

Near Abay National Park in northeast Ethiopia, the resin is crushed, mixed with butter and painted on scorpion stings.

Great yellow gentian

Gentiana lutea

In Iranian traditional medicine, gentian roots (the texts cover several Gentiana species) were applied with vinegar to scorpion and viper bites and taken as an antidote to animal venoms. There is no evidence this works; venomous bites need emergency treatment.

Indian borage

Coleus amboinicus

Fresh leaves are rubbed on insect bites, burns, bruises and skin inflammation in several countries; a 20% oil solution repelled Aedes mosquitoes as well as DEET for up to 6 hours in one study.

Indian snakeroot

Rauvolfia serpentina

Folk use against snake and insect bites, listed by WHO as unsupported.

Lantana

Lantana camara

Leaves are burned as a mosquito and insect repellent in Kenya, Nigeria and Uganda (prevention of bites, not treatment).

Lemongrass

Cymbopogon citratus

The most cited mosquito-repellent plant in a Guadeloupe survey; the essential oil is used as an insect repellent.

Mapacho

Nicotiana rustica

Cherokee healers applied a poultice of the beaten plant to boils and insect bites, and Iroquois a poultice of the chewed plant to insect bites; the juice was put on snakebite.

Narrow-leaved coneflower

Echinacea angustifolia

Plains nations used the root for snakebite and venomous bites and stings (Omaha: a poultice of smashed roots); late-nineteenth-century American physicians also used it for poisonous bites.

Onion

Allium cepa

Applied externally in European folk medicine for insect bites, wounds, minor burns, boils, warts and bruises; not tested in trials.

Portia tree

Thespesia populnea

Kani and Irula communities in Tamil Nadu apply fruit juice or crushed fruit to insect bites.

Ribwort plantain

Plantago lanceolata

Listed in European handbooks for insect stings, and by the Cherokee as a poultice for stings and an infusion for poisonous bites. No clinical testing.

Rue

Ruta graveolens

Chinese texts record it for insect and snake bites ('managing snake wounds'); leaf extracts slowed snake-venom-induced clotting in a lab test.

Sea hibiscus

Hibiscus tiliaceus

In French Polynesia boiled flowers are used to bathe children with chickenpox and skin infections from mosquito bites (one or two reports each).

Snake grass

Clinacanthus nutans

Fresh leaves are a traditional remedy for snake, scorpion and insect bites and skin rashes.

Spearmint

Mentha spicata

Traditional Persian medicine lists na'na' among antidotal plants for scorpion venom and dog bites. Not a substitute for emergency treatment.

Tea tree

Melaleuca alternifolia

EU traditional-use indication alongside small wounds; Aboriginal use of the leaves for insect bites is recorded by NCCIH and EMA.

Tobacco

Nicotiana tabacum

A Cherokee poultice of the beaten plant was applied to insect bites, and the juice to snakebite.

Wild dagga

Leonotis leonurus

Decoctions are used for spider and snake bites.