Raised O-shaped rashes on my ankle, knee and thigh

[kg984293]

I have an O-shaped, slightly raised, reddish purplish rash on my right ankle, left knee, and more recently on my inner right thigh.  They are not painful, not itchy, just unsightly.  The patches on my ankle and knee have been there for 2+ years, and the one on my knee has grown a bit (it's now a snowman shape).  I noticed the one on my thigh about a week ago.  It started off as a few dots of redness, then expanded into an O.   What is going on?

[maatson]

No harm getting tested,all routine by the way.
Cheers!

[kg984293]

You were correct!  Granuloma annulare, confirmed with a biopsy.  Treating with steroid creams now.  The dermatologist also recommended getting tested for diabetes (no other risk factors: I'm not obese, no unusual thirst, no family history).  Should I get checked?

[maatson]

While the differential diagnosis would range from annular lichen planus(unlikely,no itching) to lyme erythema migrans(does not persist for this long), and vasculitis(leaves behind pigmentation), it would be prudent to get a biopsy for more clarity on the condition.
Regards.

[Arti Sharma, M.D.]

Hello and welcome!
I cannot confirm anything without an external examination. There can be several causes of these reddish purplish rashes .The common causes are allergic purpura .It is a form of vasculitis in which there is inflammation of the small arterial vessels in the skin, kidneys, and intestinal tract and purple spotted skin rash. It often develops after a recent viral or bacterial infection of the respiratory tract and may be an abnormal reaction of the immune system to the infection. The other possibility is Lyme disease. In this condition there may be rash before the onset of fever. The rash is circular and called erythema migrans. Other possibility is southern tick associated rash illness .It is best to get it seen by a dermatologist. A clinical examination and investigations like platelet count may be needed. Do keep us posted.
Take care and best regards!

[maatson]

Granuloma annulare is my impression.

[Bhupinder Kaur, MD]

Hello,
For your symptoms, lichen planus should be ruled out. Lichen planus is an inflammatory disease that affects the skin and the oral mucosa, and presents itself in the form of papules(flat spots) or rashes. It is a papular eruption characterized by its violaceous color.
Treatment is available only on prescription and consists mainly of steroids,retinoids,hydroquinone and phototherapy.

It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.