First things first – you can certainly tell your dermatologist that you are keen on a patch test the next time you visit him, especially with your recent flare up. He will tell you why it is or isn’t indicated for your situation. But even so, the test needs to be done on clear skin, meaning you need to get your eczema under control first before the patch test can be carried out.
The reason why your doctor prescribed steroid cream is because that’s the correct treatment for your eczema. Even if you do a patch test, it will simply tell you what you need to avoid, but will not get rid of your ongoing active eczema.
As to the second part of your question – in a nutshell, patch tests are only performed in patients with eczema when a) you have a history strongly suggestive of a specific trigger for your eczema, or b) a trial of treatment for your eczema doesn’t work.
Patch tests are not done routinely for eczema because the results can be rather non-specific.
From your history alone, your doctor should be able to tell if there’s a specific trigger for your rash breakouts. He will then do a patch test to confirm it.
Conversely, if you’ve had a long history of atopic eczema, patch tests are unlikely to be helpful and may even produce “false positives”, ie results that indicate you are allergic to something that you actually aren’t allergic to!
I hope you get your eczema under control soon! I know what a pain it can be, as a former sufferer myself. I wrote some important things to note about eczema here.
Cheers
