<<forEachTiddler where 'tiddler.tags.contains(context.inTiddler.title)' sortBy tiddler.title ascending write '"*[["+tiddler.title+"]]\n"'>> <<tiddler AutoRefresh with: force>> ''Skin prick'' Most common easy to perform, inexpensive Drops diluted allergen placed on skin which is then pierced using a needle large number of allergens tested in one session includes controls - histamine (positive), sterile water (negative) wheal will typically develop by 15 mins if allergy Useful for food allergies and pollen ''Radioallergosorbent test (RAST)'' Determines the amount of IgE that reacts specifically with suspected or known allergens eg to egg protein Results given grades from 0 (negative) to 6 (strongly positive) Useful for food allergies, inhaled allergens (e.g. Pollen) and wasp/bee venom Blood tests used when skin prick tests are not suitable eg extensive eczema or on antihistamines ''Skin patch'' Contact dermatitis. 30-40 allergens on back Irritants may also be tested for. removed 48 hours and results read by dermatologist after a further 48 hours