Zinc oxide barrier ointment (10–40%)

What It Is

Zinc oxide barrier ointment is a semi-occlusive skin protectant containing 10–40% zinc oxide dispersed in a fatty base (often petrolatum, lanolin, white wax, mineral oil). It is used topically on intact or superficially irritated skin to prevent and treat moisture-associated skin damage such as diaper dermatitis, incontinence-associated dermatitis, peristomal skin irritation, and other low-grade irritant rashes. At higher concentrations the product tends to be thicker, whiter, and more persistent on skin.

How It Works

Zinc oxide acts primarily physically rather than pharmacologically:

1. Barrier — It creates a persistent, water-repelling yet semi-breathable film that shields epidermis from urine, stool, sweat, and wound exudate.
2. Micro-environment modulation — By separating skin from irritants, it allows physiologic repair and reduces further breakdown. Its mild astringency can reduce local weeping.
3. Mild antimicrobial/anti-inflammatory activity — Zinc ions have low-grade antimicrobial and calming effects that can support healing of superficial irritation, though this is secondary to barrier function.

Why It’s Important

Moisture and irritants macerate the stratum corneum, rapidly degrade barrier proteins/lipids, and lower pH, setting up a cycle of pain, erosion, secondary infection, and impaired healing. Wet/incontinent skin breaks down faster than pressure alone. By breaking the exposure loop, zinc oxide:

• Curtails the progression from redness to erosions/ulceration
• Reduces nociceptive irritation and improves patient comfort
• Lowers the risk of Candida and bacterial overgrowth in chronically moist areas
• Makes other preventive bundles (e.g., repositioning, continence care) more effective by preserving the skin barrier

Considerations

Concentration and Handling

Higher % pastes (20–40%) are more durable for heavy moisture, but they are stiffer to spread and harder to remove; over-cleaning to “get it all off” paradoxically re-injures the skin. The correct practice is to gently wipe away only the soiled top layer and leave the clean under-layer in place, then re-topcoat.

When Not to Use

Do not apply over clinically infected, deep, or ischemic wounds without guidance. Suspected fungal dermatitis sometimes benefits more from antifungal barrier combinations than pure zinc oxide alone. Avoid if true contact allergy to a base component (rare to zinc itself, more often to lanolin or fragrance if present).

Application Technique

Apply a thin, even film—“frosted glass” look is adequate; thicker is not necessarily better if the film is even and replenished frequently. Re-apply with any soiling or cleansing. Pair with moisture-management strategies (continence control, absorbent products, airflow).

Integration With Cleansing

Cleanse with lukewarm water or a pH-balanced, no-rinse cleanser; avoid harsh soaps, alcohol, vigorous friction, or repeated removal cycles of the paste. Pat—do not rub.

Cosmetic/Practical Issues

White residue can mark linens/garments; product may occlude ostomy adhesive surfaces if placed too close to wafer borders. Select formulations labeled “stoma-compatible” when used peri-ostomy.