A&D ointment is not antifungal. It contains no antifungal active ingredients and will not treat a fungal infection on the skin. Its two active ingredients, petrolatum (53.4%) and lanolin (15.5%), form a moisture barrier that protects irritated skin and helps it heal, but they have zero ability to kill or inhibit fungus. This distinction matters because using A&D on a fungal rash can actually make things worse.
What A&D Ointment Actually Does
A&D ointment is classified as a skin protectant. Petrolatum and lanolin work together to create an occlusive layer on the skin’s surface, which instantly reduces water loss and shields raw or irritated skin from further contact with moisture and friction. The inactive ingredients include cod liver oil (the source of vitamins A and D that give the product its name), light mineral oil, microcrystalline wax, and paraffin.
This makes A&D effective for ordinary diaper rash, minor chafing, and dry or cracked skin. It keeps irritants out while the skin repairs itself underneath. But protection and treatment are different things. A&D creates a physical barrier. It does not contain any compound that targets the organisms causing a fungal infection.
Why A&D Can Make Fungal Rashes Worse
Fungal infections thrive in warm, moist environments. The same occlusive barrier that makes A&D helpful for regular irritation can trap heat and moisture against the skin, creating exactly the conditions fungus needs to grow. If you apply A&D ointment to a yeast or fungal rash, you may notice the rash spreading or intensifying rather than improving. Medical references on diaper dermatitis place petrolatum-based products and antifungal agents in completely separate treatment categories for this reason.
How to Tell if a Rash Is Fungal
The most common fungal skin rash, especially in the diaper area, is caused by Candida yeast. It looks noticeably different from standard contact irritation. A yeast rash produces bumpy, pimple-like skin that can appear shiny, cracked, or oozy, often with a deep red or purple tone. It tends to settle into skin folds near the groin, legs, and genitals, and may show up as several smaller patches scattered across the diaper region.
Regular diaper rash, by contrast, typically appears as a single patch on a larger surface like the buttocks. The skin looks dry, scaly, or smooth with a lighter pink tone. If A&D ointment isn’t improving a rash within a few days, or the rash is worsening, a fungal infection is one of the most likely explanations.
What Actually Treats Fungal Skin Infections
Over-the-counter antifungal creams contain active ingredients specifically designed to kill fungus on the skin. The most widely available option is clotrimazole, sold under brand names like Lotrimin. Miconazole (found in Monistat and some Lotrimin products) is another common choice. Both are applied twice daily, morning and evening, directly to the affected area.
These antifungals come in cream, lotion, or solution forms. Creams are generally preferred over thick ointments for fungal infections because they don’t seal in moisture the way petrolatum-based products do. Nystatin is another antifungal sometimes used for yeast rashes, though it typically requires a prescription.
The key difference: antifungal creams contain compounds that disrupt the cell membranes of fungi, actually killing the organisms responsible for the infection. A&D ointment has no such mechanism. It simply sits on the skin’s surface as a physical barrier.
When A&D Is the Right Choice
A&D ointment works well for what it’s designed to do. For routine diaper rash caused by prolonged contact with a wet diaper, the label recommends applying it liberally with each diaper change, especially at bedtime or whenever exposure to moisture will be extended. For general skin protection, you can apply it as needed to chapped, dry, or mildly irritated skin.
If symptoms last more than seven days, worsen, or clear up and return within a few days, that’s a signal the problem may not be simple irritation. A persistent or recurring rash in skin folds, particularly one that doesn’t respond to barrier ointments, is worth evaluating for a possible fungal cause and switching to an appropriate antifungal product.