Is this good news, or just news?

[wb]

We have recently received ds1's 2nd set of RAST results for his peanut allergy and I was hoping for some opinions on what they actually mean (if anything).

His RAST score for peanut has fallen from 2.8 (at age 1.5 years) to 0.8 (at age 2.5 years). So the way I understand it, it has fallen from a high-moderate (Class 2) to a low moderate (Class 2) result.

His skin prick result however remains unchanged at 5mm.

I'm under no illusion that he isn't still allergic as he had an (albeit mild) reaction to milk during a challenge with a RAST of 0.6 and a 3mm skin wheal. But is this an indication that he might be outgrowing the peanut allergy (hopeful emoticon)? Or do the skin prick results mean he as allergic as ever?

Would be very unwilling to risk a peanut challenge with these skin results regardless of how far his RAST score fell (and to be fair no-one has suggested this might be on the cards).

For peanut allergy a wheal of 8mm is taken as proof of allergy - under that they may not react and further tests are usually advisable. RAST scores for those with serious nut allergy are often in excess of 100. So it does look very hopeful that when he gets to 5 a challenge test would be worthwhile.

What does RAST stand for? I am taking dd2 for a re-test 2+years after first( and hoping to make more sense of it than last time. )

It stands for radioallergosorbent test but what it actually is, is a measurement of the amount of antibodies (IgE) in a person's blood.

You can either measure the general level of IgE or, more usefully, the level of a specific IgE - so in my son's case his IgE for peanut is currently 0.8 (can't remember the units ).

You can then compare the level you had to that you had last time, or to these tables they have to see which class of allergy you have.

BUT - this is the problem, RAST results are no use for telling you how a person will react to the allergen. You can be anaphalactic with a low RAST and not with a higher one. Generally though, the higher the RAST the more likely you are to react to even trace amounts of the allergen.

Hope this helps