Red line on thumb

[ARnola]

I noticed this red line on my thumb 5 days ago. I was at the beach, so I thought it might be a sunburn, but it has not faded any. It is very slightly raised and painless. It does not itch. Should I be concerned?

[maatson]

I do no see anything other than a Berloque dermatitis possibly relating to perfume or perhaps to a sunscreen.The post inflammatory pigmentation would fade in a couple of weeks.. Do consult your doc.

[ARnola]

Thanks for your reply. It has also appeared on my other hand and on my back. It has been over three weeks now. I have not been able to see a dermatologist. General practitioner did not know what it is. CMP was normal except low RBC. He prescribed 7 days of doxycycline, which did not help, and said to see someone else if it did not get better. The spots have started to turn brown. I guess I need to see a dermatologist.

[Arti Sharma, M.D.]

Hello!
It is possible that it is due to any allergy, inflammation or bacterial/fungal infection. Sunburn should have gradually decreased but since its persisting it is best to get it seen by a dermatologist. It is possible that it could be contact dermatitis, or an allergic reaction to parasites in and around the water. Do write to us again on what the doctor advises. Do keep us updated.
Best regards!