Sweet Itch
Equine Culicoides hypersensitivity (Sweet Itch)
Sweet itch is an allergic skin disease affecting susceptible
horses and ponies that become hypersensitive to the bites
of midges of the genus Culicoides, with different species
of midges having somewhat different preferential feeding sites
on the body surface.
The allergic reaction develops at the site of feeding, and
in the UK the majority of affected horses show skin lesions
affecting the mane and tail and dorsal midline, although ventral
midline symptoms may occur, and lesions around the ears and
head.
The problem is characterised by intense itching (pruritus),
which results in rubbing and considerable self-trauma, sometimes
with secondary infection. Control of the condition can be
problematic, with the main efforts directed towards preventing
affected horses and ponies from being bitten and symptomatic
treatment to control the effects of the allergy.
Research interest in the disease at the AHT is directed towards
identifying allergic antibodies in the blood of horses specifically
directed towards the Culicoides midges. With species-specific
detection reagents, at present unavailable for equine patients,
the definitive diagnosis of the disease could be made on a
blood sample, rather than relying clinical picture or confirmation
by intradermal skin testing. In addition, efforts are underway
to identify genetic markers linked with the disease, since
it is well recognised that the tendency to develop Sweet Itch
runs in families of horses.
To find out more about the AHT why not visit their website
www.aht.org.uk
