Foot fungus typically shows up as peeling, scaly skin between your toes, but it can also appear as thickened soles, fluid-filled blisters, or discolored toenails depending on the type and location of the infection. What makes identification tricky is that foot fungus doesn’t have just one look. There are several distinct patterns, each affecting a different part of the foot with different visual clues.
Peeling and Cracking Between the Toes
The most common form of foot fungus targets the spaces between your toes, especially the outer three (the gap between your fourth and fifth toe is the classic starting point). The skin in these areas becomes scaly, red, and eroded. In the early stages, you might notice mild flaking and itching that’s easy to dismiss as dry skin. As the infection progresses, the skin turns whitish and soggy from trapped moisture, a process called maceration. Eventually, the softened skin cracks into painful fissures that can sting when you walk or shower.
On lighter skin, the surrounding area looks pink or red. On darker skin tones, the same inflammation may appear purple, grayish, or brown rather than red. The swelling and texture changes are the same regardless of skin color, but the color shift is worth knowing so you don’t rule out a fungal infection just because you don’t see classic redness.
Dry, Thick Scaling on the Soles
A second pattern, often called the moccasin type, looks completely different. Instead of soggy, cracked skin between the toes, you’ll see a gradual thickening and scaling across the bottom of your foot. The scaling often extends up the sides of the foot in a shape that roughly matches where a moccasin shoe would sit, which is where the name comes from. The skin feels tough and leathery, with fine white or silvery flakes over a background of mild redness or irritation.
This type is easy to mistake for plain dry skin or even eczema, because it develops slowly and doesn’t always itch intensely at first. A key giveaway: if the dryness and scaling affect both feet in a symmetrical pattern and don’t improve with regular moisturizer, fungus is a likely cause. This form tends to be chronic and stubborn, often requiring longer treatment than the between-the-toes variety.
Blisters on the Inner Foot
The least common but most dramatic-looking form produces small to medium-sized fluid-filled blisters, usually on the inner arch or sole of the foot. These blisters are intensely itchy, and clusters of them can merge into larger, raised pockets of fluid. When they break, they leave raw, weeping patches that crust over as they heal. This type often flares up as a worsening of an existing between-the-toes infection rather than appearing on its own.
These blisters can look very similar to dyshidrotic eczema, a non-fungal skin condition that also causes small blisters on the feet and hands. One way to tell the difference: eczema tends to be more widespread and may involve larger areas of skin, while fungal blisters typically stay concentrated on the foot, often alongside visible scaling or cracking between the toes. If you’re treating what you think is athlete’s foot with over-the-counter antifungal cream and it isn’t improving after two to four weeks, eczema or another condition may be the actual cause.
Toenail Fungus
Fungal infections frequently spread from the skin of the foot into the toenails, where they cause a distinct set of changes. An infected toenail may turn white, yellow, reddish-brown, green, or even black. The nail thickens and becomes difficult to trim. Chalky debris builds up underneath the nail, sometimes lifting it away from the nail bed. The nail may become brittle, crumbling at the edges.
Toenail fungus almost always starts at the tip or side of the nail and works its way toward the base. In early stages, you might notice just a small white or yellowish spot near the edge of one nail. Over months, that discoloration spreads, the nail gets progressively thicker, and the texture becomes rough and uneven. Big toenails are the most commonly affected, partly because they experience the most pressure inside shoes and take the longest to grow out.
Signs the Infection Has Gotten Worse
Foot fungus itself is uncomfortable but not dangerous for most people. The real risk is that cracked, broken skin creates an entry point for bacteria. If a bacterial infection sets in on top of the fungal one, the foot may become painful, red, swollen, warm to the touch, and tender. The redness can spread quickly beyond the original area of cracked skin. Some people develop fever and chills. The skin may look pitted, similar to the texture of an orange peel, and new blisters can form.
This type of bacterial skin infection, called cellulitis, is common enough that people who get repeated episodes of cellulitis on the lower leg are routinely checked for underlying foot fungus. The CDC lists chronic skin conditions like athlete’s foot as a risk factor for cellulitis because the broken skin barrier lets bacteria through. If you notice rapidly spreading redness, increasing pain, or warmth radiating from your foot, that’s a sign the infection has moved beyond fungus alone.
How to Tell It Apart From Dry Skin or Eczema
The overlap between foot fungus and other skin conditions is real. Both eczema and fungus can cause dryness, flaking, discoloration, and itching. A few practical differences help narrow it down. Fungal infections tend to concentrate in specific zones: between the toes, across the sole in a moccasin pattern, or on the inner arch. Eczema is typically more widespread and often affects other parts of the body too, particularly around larger joints. Eczema patches tend to feel rough and leathery with visible swelling, while fungal scaling is finer and flakier.
Location matters more than any single visual clue. If the problem is isolated to the web spaces between your toes or follows the sole-and-sides moccasin pattern, fungus is the most likely explanation. If it’s patchy and scattered across the foot or involves the tops of your toes and ankle, other conditions move higher on the list. When there’s genuine uncertainty, a simple skin scraping examined under a microscope can confirm whether fungus is present. The sample is taken from the most heavily infected area or the active, advancing edge of the rash.