Isotretinoin vs. Doxycycline for Rosacea: Comparing Effects on Skin Inflammation Markers | Research

The takeaway

Both isotretinoin and doxycycline reduced inflammatory biomarkers in rosacea skin, but through different mechanisms.

40 patients
Randomized comparative trial with immunohistochemical analysis at baseline and 4 months

What the researchers found

Both isotretinoin and doxycycline effectively reduced cutaneous inflammatory biomarkers in rosacea, but through distinct biological pathways.

Why it matters

Understanding how these drugs work at the molecular level helps dermatologists choose the best treatment for individual rosacea patients.

The numbers in context

40 participants. Doxycycline 100 mg vs isotretinoin 0.3 mg/kg daily. 4-month treatment. VEGF vessel count reduced with doxycycline (P=0.010). VEGF intensity reduced with both. LL-37/cathelicidin expression reduced.

How the study worked

Randomized, comparative, evaluator-blinded trial with immunohistochemistry at baseline and 4 months in 40 participants.

Who was studied

Adults with moderate-severe papulopustular rosacea

What this study cannot tell us

Relatively small sample (40 patients). 4-month timeframe may not capture long-term effects or relapse patterns.

How to read the evidence

Randomized comparative trial with objective biomarker outcomes — moderate evidence strength for a focused dermatology question.

When this study was published

Published in 2025, adding molecular-level data to rosacea treatment decisions.

The bigger picture

By revealing distinct mechanisms, this study supports personalized rosacea treatment based on individual disease characteristics.

Questions still open

Which drug is better for specific rosacea subtypes based on biomarker profiles?
Do the different mechanisms predict different relapse rates?

Common questions

Is isotretinoin effective for rosacea?

Yes — this study showed it reduces inflammatory biomarkers in rosacea skin, working through sebaceous gland suppression and toll-like receptor modulation.

How does doxycycline treat rosacea?

Doxycycline works primarily through anti-inflammatory mechanisms rather than its antibiotic properties, reducing skin inflammation markers in rosacea.

Read the original research

A comparative exploration of immunohistochemical markers in patients with papulopustular rosacea undergoing treatment with oral isotretinoin versus doxycycline.

International journal of dermatology, 64(3), 546-551

View on PubMed ↗Publisher’s paper ↗

Citation

Picosse, Fabíola; Rocha, Marco Alexandre; Costa, Caroline Sousa; Enokihara, Milvia Maria Simões E Silva; Sanudo, Adriana; Bagatin, Ediléia. (2025). A comparative exploration of immunohistochemical markers in patients with papulopustular rosacea undergoing treatment with oral isotretinoin versus doxycycline.. International journal of dermatology, 64(3), 546-551. https://doi.org/10.1111/ijd.17420