Pruritus refers to itching felt in any body part, which can feel painful at times. There are several temporary conditions that involve pruritus, which can be viral or bacterial and goes away as the infection clears. Chronic skin conditions that result in pruritus and inflammation include eczema and psoriasis.
Eczema (or dermatitis) is an itching, swelling rash on the skin that suddenly appears and becomes inflamed, dry and thickened. There may be encrusted scaling lesions or patches of redness. It can be triggered by an allergic reaction to something touched (contact dermatitis) or result from internal allergies to food or something in the environment. 3-7% of the population has eczema and there is a genetic predisposition as well as a link to other allergy problems.
Eczema/Pruritus and Cannabis
NOTE FOR FIRST TIME READERS: Cannabinoids – such as THC, CBD – and terpenes are the main medically active components in cannabis (aka marijuana). For more information on these components, and much more about the plant, see our section on the Science of Cannabis.
In 2003 British researchers reported that the peripheral administration of a synthetic cannabinoid significantly reduced itching (induced for the experiment) in 12 subjects. In 2006 German researchers reported that 22 patients with prurigo, lichen simplex and pruritus who applied an emollient cream with a cannabinoid (e.g. cream or ointment) reduced itching by an average of 86.4%. “Topical cannabinoid agonists represent a new effective and well-tolerated therapy for refractory itching of various origins. Creams with a higher concentration may be even more effective with broader indications.” One study showed that topical THC helped mice heal faster from skin allergies, while also acted as an anti-inflammatory.
The use of topical cannabis for skin disorders ranging from itching to scaling, swelling and redness has been gaining popularity among medical marijuana patients. Often they can substitute for steroid creams or other medications. In general topical cannabis is the preferred delivery method for skin conditions. Balms and salves that have less water content are preferred for eczema treatment. Both THC and CBD cream are effective for dermatitis.
Richardson J, Kilo S, Hargreaves K. Cannabinoids reduce hyperalgesia and inflammation via interaction with peripheral CB1 receptors. Pain. 1998, 75(1): 111-9.
Stander S, Reinhardt HW, Luger TA, Topical application of a cream with N-palmitoyl ethanolamine had a good antipruritic effect in most patients. Hautarzt. 2006, Jul 28.
Karsak M, et al. Attenuation of allergic contact dermatitis through the endocannabinoid system. Science. 2007, 316(5830): 1494 – 1497.