Sakitamiwa Classification [updated]
While originally established for upper gastrointestinal (GI) tract pathology, the utility of the Sakita-Miwa scale has expanded seamlessly into evaluating lower intestinal ulcers, post-endoscopic resections, and localized inflammatory diseases. Understanding this grading metric is essential for gastroenterologists worldwide to accurately differentiate acute, high-risk ulcerations from benign, healing tissue. Structural Breakdown of the Sakita-Miwa Classification
[ Active Stage ] ----------> [ Healing Stage ] ----------> [ Scarring Stage ] ├── A1: Acute Slough ├── H1: Mucosal Bridging ├── S1: Red Scar └── A2: Defined Margins └── H2: Converging Folds └── S2: White Scar 1. The Active Stage (A-Stage)
Patients staged within 48 hours of fever onset who receive stage-appropriate therapy (e.g., early ribavirin for Stage I; plasma exchange for Stage III) have a 54% relative risk reduction in progression to Stage IV (NNT = 6). Importantly, the Classification also identifies a subset of (> 5,000 ng/mL) – termed "Sakitamiwa Macrophage Activation Syndrome" – which responds to anakinra (IL-1 blockade) but not corticosteroids.
The body begins to repair the tissue, and the ulcer significantly reduces in size. Intestinal Research H1 (Healing-1): sakitamiwa classification
The is a standardized medical staging system used primarily in East Asian clinical practice to evaluate the healing process of gastric and duodenal ulcers. It breaks down the "life cycle" of an ulcer into six distinct stages categorized under three main phases: Active, Healing, and Scarring. Active Phase (A)
The ulcer is deep with a thick, white or yellowish-gray coating (slough) at the base. The margins are sharp and often swollen with edema.
The ulcer is deep with a thick white or yellow slough (exudate) at the base. The margins are sharp and often swollen, sometimes referred to as the "lip-like sign". The Active Stage (A-Stage) Patients staged within 48
: The dense white slough coating on the floor becomes noticeably thin. Regenerating epithelium begins migrating from the margins, covering less than 50% of the original ulcer base. Converging mucosal folds can now be clearly seen traveling directly toward the edge of the ulcer crater.
The ulcer is deep with a distinct white coating (exudate) and a surrounding edematous, inflamed border.
In modern research, doctors often assign numerical scores to these stages to quantitatively measure improvement. For example, a study on ischemic colitis or Behçet’s disease might use the following scale: Clinical Meaning Numerical Score (Example) Highly Active / Deep A2 Active / Slightly Improved H1 Early Healing H2 Advanced Healing S1 Red Scar (Healed) S2 White Scar (Mature) Why is this Classification Important? Intestinal Research H1 (Healing-1): The is a standardized
The scarring phase indicates the ulcer has healed completely and a scar has formed. This does not mean the mucosa is identical to its original state, but that the continuity of the epithelial lining has been restored.
A validated point-of-care score – the – combines age > 55 years, platelet count < 70,000/μL, and a positive non-structural protein 1 (NS1) antigen result. SSI ≥ 4 predicts Stage III with 89% sensitivity.