the ideal is both, esp at the start of diagnosis, skin prick tests are cheaper than blood tests and give instant , visable results, blood tests take 2 weeks for results.
for older teens seeing the hives from skin prick tests is a very visable reminder, if they havent had a reaction for years.
in the case of peanut, skin prick tests are very accurate. however , reaction status varyies considerably with each exposure. consided unpredicatable in reagard to reaction status.
both can give false positive and negatives, which is why doctors take reaction history in to account.
we have had blood tests at the start, and now for some years have had skin prick tests. after lowering skin prick tests or negative ones, we have had the chance to consider food challenges.
extreme side effects to skin prick tests are very rare, and considered safe for vast majority. a very small few have had more of a problem with them , but on the whole are very safe.