Unusual pentagon shaped marks on body

What would cause pentagon shaped marks on the body? It started with one large mark and has spread so that there are additional small marks that are growing larger.

[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.
Hope it helps. Take care and do keep me posted on how you are doing or if you have any additional queries. Warm regards.