Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concerns..
As per your complain it seems that pigmentation, burning and inflammation of lips seems to be due to allergic reaction
only and in case if you do not know what is causing allergic reaction you should consult an Allergist or an Immunologist and get evaluated and he can do a thorough clinical evaluation and also do allergy tests
like Patch test
, food challenge test and RAST test to rule out the exact cause of allergy and after knowing the exact allergen preventing exposure to it can help..
In case if still you get frequent exposures an Immunotherapy
can be given to reduce the severity of allergic reaction..
As of now take anti allergic medicine like Zyrtec and do cool compresses over the lips..
You can also apply lignocaine gel that is a numbing gel to relieve burning and pain..
Avoid spicy food, sun exposure and drink plenty of water..
Do not use any lip cosmetics and if there is dryness apply cooled aloevera
Hope this information helps..
Thanks and regards.
Dr.Honey Nandwani Arora