Alopecia areata patch size fluctuates rapidly, and weekly AI tracking creates a precise size history that dermatologists value far more than subjective descriptions. By measuring patch boundaries every 2 weeks, you can detect whether a patch is expanding, stable, or regrowing before the change becomes obvious to the naked eye.
How Patch Boundary Tracking Works
AI boundary mapping analyzes your patch photographs to calculate the surface area of each hairless region. When you upload consistent photos every 2 weeks, the system compares boundaries across sessions and calculates the percentage change.
A patch that measured 3.2 cm in diameter at week 0 and 2.8 cm at week 4 has shrunk by approximately 12.5%. That level of precision helps you and your dermatologist decide whether treatment is working before waiting the typical 3 to 6 months for visible regrowth.
What to Look for in Each Photo Session
Every 2-week session should document three key indicators for each patch:
1. Patch boundaries. Are the edges sharp or diffuse? Sharp, well-defined borders with no broken hairs suggest stable or inactive disease. Diffuse edges with exclamation mark hairs (short, tapered hairs that narrow at the base) indicate active hair loss.
2. Surface texture within the patch. Smooth, shiny skin suggests no regrowth activity. A slightly rough or fuzzy texture may indicate early vellus hair emergence.
3. Hair quality at the margins. Terminal hairs growing inward from the edges signal regrowth. White or light-colored vellus hairs within the patch often precede pigmented terminal hair recovery.
Tracking Treatment Response by Patch
If you have multiple patches, each one may respond differently to treatment. Create a simple tracking table:
| Patch ID | Location | Week 0 Size | Week 4 Size | Week 8 Size | Status |
|---|---|---|---|---|---|
| P1 | Left temporal | 3.2 cm | 2.8 cm | 2.1 cm | Shrinking |
| P2 | Vertex | 1.5 cm | 1.5 cm | 1.4 cm | Stable |
| P3 | Right occipital | 0.8 cm | 1.2 cm | 1.6 cm | Expanding |
This per-patch data tells your dermatologist which areas need more attention. Patch P3 above is expanding despite treatment, which may warrant a targeted intralesional injection at that specific site.
When Your Data Signals a Treatment Change
Your tracking data supports a treatment change discussion when:
- Any patch expands by more than 20% over 4 weeks
- New patches appear during active treatment
- No measurable improvement after 12 weeks of consistent therapy
- Patches that were stable begin expanding again (relapse signal)
Share these specific data points with your dermatologist. Objective measurements carry more weight than "it seems like it's getting worse" in clinical decision-making.
Photography Tips for Accurate Patch Tracking
Consistent photography is the foundation of reliable tracking.
- Same lighting: Natural window light or a consistent lamp from the same direction
- Same distance: 6 to 8 inches from the patch surface
- Same angle: Directly above the patch whenever possible
- Scale reference: A coin or ruler placed next to the patch in every photo
- Clean scalp: No styling products, dry hair, surrounding hair parted fully away from the patch
Medical Disclaimer
This article is for informational purposes only and does not constitute medical advice. Alopecia areata requires professional diagnosis and treatment. Consult a board-certified dermatologist for personalized treatment recommendations.
Start Mapping Your Patches
Upload your patch photos to myhairline.ai/analyze to begin AI-assisted boundary tracking. Consistent measurements every 2 weeks build the data record that drives better treatment decisions.