What could cause red dry circular patches on my thighs and calves that do not itch?

Hi,

Welcome to icliniq.com.

I have read your query and understand your concern. I have reviewed your picture (attachments removed to protect patient privacy). It seems you have pityriasis rosea or rosea from drug eruptions. Pityriasis rosea (PR) is a self-limiting eruption, which means it will subside on its own after a specified duration if not treated. The exact cause is unknown, though the following factors may be relevant:

1. Infection - A relationship with recent upper respiratory infections has been recorded and some studies have demonstrated the presence of HHV 7 (Human herpes virus).

2. Drugs - Metronidazole, Gold, Isotretinoin, Captopril, Bismuth, Arsenic, Barbiturates, Clonidine, and Omeprazole have been reported to cause PR or PR-like rashes, often with atypical features and a protracted course. Pityriasis rosea-like eruptions can also occur following Hepatitis B and BCG vaccination (Bacillus Calmette-Guerin).

3. Other factors - Atopy, Seborrheic dermatitis, and Acne vulgaris are more common in patients with PR.

In classic Pityriasis rosea, the primary eruptions also called herald patch or mother patch, are seen in 50 to 90 percent of cases on their covered truncal area. As Pityriasis Rosea is self-limiting, I suggest using topical corticosteroid Mometasone over the body twice for two weeks, after consulting your doctor or nearby dermatologist.

I hope this information will help you. Please revert in case of further queries.

Thank you.