red blotche

I have this red medium size blotche on my upper thigh.  It's been there for the past month and I don't know why I have it.  I'm not allergic to anything and I have recently changed my diet.  May that have somthing to do with it?

[Bhupinder Kaur, MD]

Hello,
Without examination, confirmation of a diagnosis is tough but it can be pityriasis rosea.

Pityriasis rosea is a common human skin disease which presents as numerous patches of pink or red oval rash. The rash may be accompanied by low-grade headache, fever, nausea and fatigue and sometimes by itching.

No treatment is usually required. In most patients, the condition lasts only a matter of weeks or months (upto six months)

If the rash persists then it will be best to get it evaluated from a dermatologist. Other possibilities have to be ruled out then.
I hope it helps. Take care and please do keep me posted in case you have any additional doubts. Kind regards.