Foot fungus typically shows up as peeling, flaking skin between the toes, but it can look very different depending on the type. Some forms cause dry, scaly soles that resemble dry skin, while others produce fluid-filled blisters. Knowing which pattern you’re looking at helps you figure out what you’re dealing with and whether that stubborn patch on your foot is actually fungus or something else entirely.
Between the Toes: The Most Common Type
The interdigital form is the one most people picture when they think of athlete’s foot. It shows up as red, peeling, soggy-looking skin in the spaces between your toes, most often between the fourth and fifth (the two smallest). The skin in the toe web turns white and soft from trapped moisture, a process called maceration, and small cracks or splits can form in the creases. You’ll often notice flaking or scaling around the edges.
In more advanced cases, the cracks deepen into painful fissures, and the surrounding skin becomes raw and eroded. The area may itch or burn, especially after you take off shoes you’ve been wearing all day. If the cracked skin starts to ooze, smell foul, or develop a yellowish crust, bacteria have likely moved into the broken skin on top of the fungal infection.
Dry, Scaly Soles: Moccasin-Type Fungus
This form is easy to miss because it doesn’t look like an infection. It appears as a fine, dry scale covering the bottom of your foot, sometimes with mild redness underneath. In its full form, the scaling covers the entire sole and wraps up the sides of the foot while leaving the top completely clear. The pattern looks exactly like you’re wearing a moccasin, which is where the name comes from.
In earlier or milder cases, the scaling may only stretch from the toes to the middle of the sole, covering roughly half the bottom of the foot. The skin feels rough and slightly thickened but usually isn’t very itchy. Many people assume they just have dry feet and reach for moisturizer instead of antifungal treatment, which is why this type tends to become chronic. It can persist for months or years without being recognized.
Blisters and Bumps: The Inflammatory Type
The vesicular type looks nothing like the other forms. Instead of dry or peeling skin, it produces clusters of small, fluid-filled blisters. These typically appear on the soles of the feet but can show up anywhere on the foot’s surface. The blisters range from tiny pinpoint bumps to larger pockets of clear fluid, and the surrounding skin is often red and inflamed.
This type tends to flare suddenly and can be quite uncomfortable. The blisters eventually break open, leaving raw, weeping patches that dry into crusts. Because it looks more like a rash or allergic reaction than a typical fungal infection, it’s frequently misdiagnosed.
When Fungus Spreads to the Toenails
Foot fungus often migrates to the toenails, especially if the skin infection goes untreated. The earliest sign is a white or yellow-brown spot that appears under the tip of the nail. It’s small and easy to ignore at first.
As the fungus works deeper into the nail, changes become harder to miss. The nail thickens noticeably, sometimes enough that it’s difficult to trim. The color shifts to yellow, brown, or even greenish. The texture becomes brittle, crumbly, or ragged at the edges, and the nail may develop a misshapen appearance. In advanced cases, the nail separates from the nail bed underneath, lifting up at the edges. A foul smell from the affected nail is common once the infection is well established. Toenail fungus grows slowly, so these changes develop over weeks to months rather than days.
Foot Fungus vs. Psoriasis
Psoriasis on the feet can look strikingly similar to moccasin-type fungus, with thick, scaly skin on the soles. A few differences help separate them.
- Pattern: Psoriasis usually affects both feet symmetrically. Fungus often starts on one foot and may spread to the other later.
- Texture: Psoriasis plaques tend to be raised, inflamed, and rough, with deeper, more painful cracks that sometimes bleed. Fungal scaling is typically finer and flatter.
- Moisture: Fungal infections often produce peeling, flaking, or moist skin, particularly between the toes. Psoriasis is generally dry.
- Other clues: Psoriasis frequently appears elsewhere on the body at the same time, such as the elbows, knees, or scalp. Psoriasis-related nail changes include tiny pits or dents in the nail surface, which fungal infections don’t cause.
If you’re unsure, a doctor can scrape a small sample of skin from the affected area and examine it under a microscope. A chemical solution dissolves the skin cells, making fungal threads visible if they’re present. The test is quick, painless, and gives a definitive answer.
Signs the Infection Is Getting Worse
Most foot fungus stays superficial and responds to over-the-counter antifungal creams. But when cracks in the skin allow bacteria in, the situation changes. Warning signs of a secondary bacterial infection include increasing redness that spreads beyond the original area, pus or cloudy drainage, swelling, warmth, and a foul odor. Red streaks traveling up from the foot toward the ankle suggest the infection is moving into deeper tissue.
People with diabetes need to pay closer attention. Reduced sensation in the feet means cracks and sores from a fungal infection can go unnoticed, and poor circulation slows healing. The CDC lists fungal infections between the toes as a specific reason for diabetic patients to see their doctor, because even minor skin breakdown on the foot can progress to ulceration. Thick, discolored toenails, dry cracked skin, and any change in foot color or temperature all warrant a visit.