Acetic Acid

證據等級: L5

預測適應症: 9 個

Acetic Acid: From Topical Antimicrobial to Tinea Corporis

Analyst Note: TxGNN’s highest-ranked prediction (rank 1) for Acetic Acid is post-bacterial disorder (score 99.98%), but this report features tinea corporis (rank 9, score 99.25%) — the only indication with an actionable recommendation (“Research Question”) and the strongest direct clinical evidence (Level L3). All eight higher-ranked predictions carry a “Hold” recommendation at L4–L5 evidence, with no direct acetic acid involvement identified in any retrieved trials or literature.

One-Sentence Summary

Acetic acid is a well-established topical antimicrobial agent used broadly in wound care, ear infections (otitis externa), and cervical cancer screening; detailed original indication data from Malaysian NPRA regulatory records was not available for this candidate. Among all nine TxGNN-predicted indications, tinea corporis carries the most direct evidence — anchored by a 2023 RCT using a vinegar-based preparation, three historical clinical series (1946–1947) documenting dilute acetic acid for dermatophyte infections, and in vitro antifungal confirmation — with approximately 8 directly relevant publications identified. This places tinea corporis at the Research Question stage, warranting a dedicated prospective trial before clinical deployment.

Quick Overview

Item	Content
Original Indication	Not available from Malaysian NPRA records
Predicted New Indication (Featured)	Tinea Corporis (TxGNN Rank 9)
TxGNN Rank 1 Prediction	Post-Bacterial Disorder (99.98%, L4, Hold)
TxGNN Prediction Score	99.25%
Evidence Level	L3
Malaysia Market Status	✓ Marketed
Number of Registrations	7
Recommended Decision	Research Question

Why is This Prediction Reasonable?

Currently, detailed mechanism of action data is not available in this Evidence Pack. Based on established pharmacology, acetic acid (CH₃COOH) exerts its antimicrobial activity primarily through pH-mediated microbial disruption: topical application reduces the skin surface pH to ≤4.5, a threshold that impairs cell membrane integrity, intracellular enzyme function, and spore germination in dermatophytic fungi — particularly Trichophyton rubrum, T. mentagrophytes, and Microsporum canis, the primary causative agents of tinea corporis.

Tinea corporis is a superficial dermatophyte infection of glabrous (non-scalp, non-beard, non-groin, non-hand/foot) skin. Because the responsible fungi are structurally and physiologically analogous to those susceptible to low-pH environments at other anatomical sites, the antifungal logic translates directly to the body surface. A 2016 in vitro study (PMID 26857689) confirmed antifungal activity of acetic acid-containing topical preparations against T. mentagrophytes. A 2002 laboratory study (PMID 16233325) further demonstrated that fermented herb products — containing acetic and other organic acids — inhibit T. rubrum, and that neutralisation of the pH abolishes this effect, mechanistically pinpointing the organic acid component as the active driver.

It is important to be precise about extrapolation limits: the most direct clinical records historically involve tinea capitis (scalp) and tinea pedis (feet) rather than tinea corporis specifically. The 2023 RCT (PMID 37012894) enrolled patients with tinea corporis and pedis and compared a Terminalia chebula + vinegar preparation against terbinafine 1% cream. The mechanism of pH-mediated antifungal action applies equally to glabrous body skin; however, no controlled trial has yet isolated pure acetic acid monotherapy for tinea corporis — which is precisely why this remains a Research Question rather than a Go decision.

Clinical Trial Evidence

Currently no related clinical trials registered for acetic acid in tinea corporis.

Literature Evidence

PMID	Year	Type	Journal	Key Findings
37012894	2023	RCT	Drug Metab Pers Ther	Terminalia chebula + vinegar demonstrated non-inferiority to terbinafine 1% cream for tinea corporis; vinegar’s acetic acid component is the principal acidic constituent proposed to underlie the antifungal effect
13616002	1958	Clinical Series	Vestn Dermatol Venerol	Earliest systematic concentration-escalation study of acetic acid for epidermophytosis (tinea pedis); directly characterises acetic acid as the active antifungal agent
20983383	1946	Historical Clinical Series	Arch Dermatol Syphilol	Foundational report of dilute acetic acid combined with special iodine for tinea capitis in clinical patients; establishes acetic acid’s historical antifungal use
20996178	1946	Historical Clinical Series	JAMA	Concurrent JAMA publication replicating dilute acetic acid efficacy for tinea capitis; publication in a high-profile journal increases historical credibility
20256868	1947	Historical Clinical Series	Urol Cutan Rev	Extended cohort confirming dilute acetic acid results for tinea capitis in a larger patient series; provides early dose-response context
28947288	2023	Case Report / Review	J Am Acad Dermatol	Contemporary narrative review of vinegar sock soak for tinea pedis and onychomycosis; contextualises self-treatment practices and modern clinical observations
26857689	2016	In Vitro Study	Mycoses	Head-to-head in vitro comparison of seven commercial topical antifungal formulations against T. mentagrophytes; confirms antifungal activity of acetic acid-based preparations relative to amorolfine reference
16233325	2002	Laboratory Study	J Biosci Bioeng	Lactic acid bacterium fermentation product (rich in acetic acid and malonic acid) inhibits T. rubrum; neutralisation abolishes activity — directly implicates organic acid / pH as mechanistic driver
8169016	1994	Diagnostic Study	Int J Dermatol	Albert’s solution (acetic acid-based reagent) compared to KOH for tinea versicolor diagnosis; establishes acetic acid’s well-documented reactivity with dermatophyte cell wall components
14510876	2003	Narrative Review	Dermatol Ther	Review of cutaneous fungal infections in the elderly including herpes zoster, onychomycosis, and antifungal management options; contextualises topical antifungal landscape within which acetic acid-based therapy sits

Malaysia Market Information

Detailed registration data was not retrievable in this Evidence Pack — all 7 NPRA authorization records were returned with empty fields across product name, dosage form, manufacturer, and approved indication.

Authorization Number	Product Name	Dosage Form	Approved Indication
—	Not retrieved	—	—

Full registration details should be obtained directly from the NPRA database to determine currently approved formulations, concentrations, and indications before any repurposing initiative proceeds.

Safety Considerations

Safety data (key warnings and contraindications) is listed as a blocking data gap in this Evidence Pack (DG001). No drug-drug interactions were identified via DrugBank query.

Skin irritation and chemical burn risk: Folk medicine use of undiluted or high-concentration acetic acid on skin has been associated with chemical burns (PMID 37256034). Therapeutic antifungal concentrations likely fall in the 2–5% range; formal tolerability and irritation profiling is essential before any clinical trial.

Please refer to the package insert for complete safety information.

Conclusion and Next Steps

Decision: Research Question

Rationale: Acetic acid’s pH-mediated antifungal mechanism is biologically direct and well-supported at the in vitro level; historical clinical evidence (1946–1958) and a 2023 RCT with a vinegar-based formulation provide meaningful clinical anchoring for tinea corporis. However, no prospective trial has investigated pure acetic acid monotherapy specifically for tinea corporis, and available studies carry significant methodological limitations (historical designs, compound preparations), justifying an L3 classification and a Research Question — not a Go — at this stage.

To proceed, the following is needed:

A dedicated randomised controlled trial comparing topical acetic acid (at defined concentrations: 2%, 3%, 5%) against standard-of-care antifungal therapy (terbinafine 1% or clotrimazole 1%) specifically for tinea corporis
Pharmacokinetic and safety profiling of topical acetic acid at antifungal concentrations — including skin tolerance, irritation threshold, contact sensitisation risk, and safe maximum concentration
Retrieval of complete NPRA registration data for all 7 Malaysian authorisations (currently a blocking data gap — DG001) to identify approved formulations and indications
Mechanism of action data from DrugBank API (DG002) to complete the mechanistic rationale and confirm absence of systemic toxicity concerns
Determination of optimal delivery vehicle (aqueous solution, cream, gel) and application frequency for practical tinea corporis treatment
Disclaimer

This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.