Mycoses are classified according to the tissue levels initially colonized.

Superficial mycoses are limited to the outermost layers of the skin and hair.

An example of such a fungal infection is "Tinea versicolor", a fungus infection that commonly affects the skin of young people, especially the chest, back, and upper arms and legs. "Tinea versicolor" is caused by a fungus that lives in the skin of some adults. It does not usually affect the face. This fungus produces spots that are either lighter than the skin or a reddish brown. This fungus exists in two forms, one of them causing visible spots. Factors that can cause the fungus to become more visible include high humidity, as well as immune or hormone abnormalities. However, almost all people with this very common condition are healthy.

In both healthy and immunocompromised hosts, Majocchi's granuloma often presents as nodules and papules on areas that are most exposed to mechanical abuse—wear and tear—such as the upper and lower extremities. Patients will complain about papules, pustules, or even plaques and nodules at the site of infection. The papules will be pink-red and will be located in a perifollicular location. Hair shafts can be easily removed from the pustules and papules. Itching is also very common. Firm or fluctuant subcutaneous nodules or abscesses represent a second form of MG that is generally observed in immunosuppressed hosts. Nodules may develop in any hair-bearing part of the body but are most often observed on the forearms, hands, and legs of infected individuals. Involvement of the scalp and face is rarely observed. Lesions start as solitary or multiple well-circumscribed perifollicular papulopustules and nodules with or without background erythema and scaling. In rare circumstances, the lesions may have keloidal features.

The initial trauma causing the infection is often forgotten or not noticed. The infection builds at the site over a period of years, and a small red papule (skin elevation) appears. The lesion is usually not painful, with few, if any symptoms. Patients rarely seek medical care at this point.

Several complications may occur. Usually, the infection slowly spreads to the surrounding tissue while still remaining localized to the area around the original wound. However, sometimes the fungi may spread through the blood vessels or lymph vessels, producing metastatic lesions at distant sites. Another possibility is secondary infection with bacteria. This may lead to lymph stasis (obstruction of the lymph vessels) and elephantiasis. The nodules may become ulcerated, or multiple nodules may grow and coalesce, affecting a large area of a limb.

As in the majority of paracoccidioidomycosis cases, pulmonary involvement results in shortness of breath, a productive cough and hemoptysis, as well as general symptoms of weight loss, fever and fatigue. Visually, lesions (as pictured) are often present, most commonly on the face.

Chromoblastomycosis (also known as chromomycosis, cladosporiosis, Fonseca's disease, Pedroso's disease, phaeosporotrichosis, or verrucous dermatitis) is a long-term fungal infection of the skin and subcutaneous tissue (a chronic subcutaneous mycosis). The infection occurs most commonly in tropical or subtropical climates, often in rural areas. It can be caused by many different types of fungi which become implanted under the skin, often by thorns or splinters. Chromoblastomycosis spreads very slowly; it is rarely fatal and usually has a good prognosis, but it can be very difficult to cure. The several treatment options include medication and surgery.

Paracoccidioidomycosis (PCM) (also known as "Brazilian blastomycosis," "South American blastomycosis,","Lutz-Splendore-de Almeida disease" and "paracoccidioidal granuloma") is a fungal infection caused by the fungus "Paracoccidioides brasiliensis". Sometimes called "South American blastomycosis", paracoccidioidomycosis is caused by a different fungus than that which causes blastomycosis.

It may have a variety of appearances; most easily identifiable are the enlarging raised red rings with a central area of clearing (ringworm). The same appearances of ringworm may also occur on the scalp (tinea capitis), beard area (tinea barbae) or the groin (tinea cruris, known as jock itch or dhobi itch).

Other classic features of tinea corporis include:

- The edge of the rash appears elevated and is scaly to touch.

- Sometimes the skin surrounding the rash may be dry and flaky.

- Almost invariably, there will be hair loss in areas of the infection.

The most common symptom of a fungal nail infection is the nail becoming thickened and discoloured: white, black, yellow or green. As the infection progresses the nail can become brittle, with pieces breaking off or coming away from the toe or finger completely. If left untreated, the skin underneath and around the nail can become inflamed and painful. There may also be white or yellow patches on the nailbed or scaly skin next to the nail, and a foul smell. There is usually no pain or other bodily symptoms, unless the disease is severe. People with onychomycosis may experience significant psychosocial problems due to the appearance of the nail, particularly when fingers – which are always visible – rather than toenails are affected.

Dermatophytids are fungus-free skin lesions that sometimes form as a result of a fungus infection in another part of the body. This could take the form of a rash or itch in an area of the body that is not infected with the fungus. Dermatophytids can be thought of as an allergic reaction to the fungus.

Onychomycosis, also known as tinea unguium, is a fungal infection of the nail. This condition may affect toenails or fingernails, but toenail infections are particularly common.

Treatment may be based on the signs. Treatment may be with the medication terbinafine.

It occurs in about 10 percent of the adult population. It is the most common disease of the nails and constitutes about half of all nail abnormalities.

The term is from Ancient Greek ὄνυξ "ónux" "nail", μύκης "múkēs" "fungus" and -ωσις "ōsis" "functional disease."

Majocchi's disease (also known as Majocchi's Granuloma, "Purpura annularis telangiectodes,", and "Purpura annularis telangiectodes of Majocchi") is well-recognized but uncommon skin condition characterized by purple/bluish-red 1- to 3-cm annular patches composed of dark red telangiectases with petechiae. The name Majocchi's comes from the Professor Domenico Majocchi who first discovered the disorder in 1883. Domenico Majocchi was a professor of dermatology at the University of Parma and later the University of Bologna. Majocchi's disease can be defined as an infection of the dermal and subcutaneous tissues due to a fungal mold infection on the cutaneous layer of the skin. The most common dermatophyte is called "Trichophyton rubrum." This disease can affect both immunocompetent and immunocompromised hosts. However, immunocompromised individuals have a higher risk.

There may be loss of hair as hair will come out easily. Sometimes, there is growth of organisms. Lymph and fever symptoms may be present. This condition can be mistaken for a case of impetigo.

Mucormycosis frequently infects the sinuses, brain, or lungs. While infection of the oral cavity or brain are the most common forms of mucormycosis, the fungus can also infect other areas of the body such as the gastrointestinal tract, skin, and other organ systems. In rare cases, the maxilla may be affected by mucormycosis. The rich blood vessel supply of maxillofacial areas usually prevents fungal infections, although more virulent fungi, such as those responsible for mucormycosis, can often overcome this difficulty.

There are several key signs which point towards mucormycosis. One such sign is fungal invasion into the blood vessels which results in the formation of blood clots and surrounding tissue death due to a loss of blood supply. If the disease involves the brain, then symptoms may include a one-sided headache behind the eyes, facial pain, fevers, nasal congestion that progresses to black discharge, and acute sinusitis along with eye swelling. Affected skin may appear relatively normal during the earliest stages of infection. This skin quickly becomes reddened and may be swollen before eventually turning black due to tissue death. Other forms of mucormycosis may involve the lungs, skin, or be widespread throughout the body; symptoms may also include difficulty breathing, and persistent cough. In cases of tissue death, symptoms include nausea and vomiting, coughing up blood, and abdominal pain.

Mucormycosis is any fungal infection caused by fungi in the order Mucorales. Generally, species in the "Mucor," "Rhizopus," "Absidia", and "Cunninghamella" genera are most often implicated.

The disease is often characterized by hyphae growing in and around blood vessels and can be potentially life-threatening in diabetic or severely immunocompromised individuals.

"Mucormycosis" and "zygomycosis" are sometimes used interchangeably. However, zygomycota has been identified as polyphyletic, and is not included in modern fungal classification systems. Also, while zygomycosis includes Entomophthorales, mucormycosis excludes this group.

Infections on the body may give rise to typical enlarging raised red rings of ringworm. Infection on the skin of the feet may cause athlete's foot and in the groin, jock itch. Involvement of the nails is termed onychomycosis, and they may thicken, discolour, and finally crumble and fall off. They are common in most adult people, with up to 20% of the population having one of these infections at any given moment.

Animals such as dogs and cats can also be affected by ringworm, and the disease can be transmitted between animals and humans, making it a zoonotic disease.

Specific signs can be:

- red, scaly, itchy or raised patches

- patches may be redder on outside edges or resemble a ring

- patches that begin to ooze or develop blister

- bald patches may develop, when the scalp is affected

- nails may thicken, discolour or begin to crack

The most common term for the infection, "ringworm", is a misnomer, since the condition is caused by fungi of several different species and not by parasitic worms.

Kerion is the result of the host's response to a fungal ringworm infection of the hair follicles of the scalp (occasionally the beard) that can be accompanied by secondary bacterial infection(s). It usually appears as raised, spongy lesions, and typically occurs in children. This honeycomb is a painful inflammatory reaction with deep suppurative lesions on the scalp. Follicles may be seen discharging pus. There may be sinus formation and rarely mycetoma-like grains are produced. It is usually caused by dermatophytes (fungal infections of the skin affecting humans and animals) such as "Trichophyton verrucosum", "T. mentagrophytes", and "Microsporum canis". Treatment with oral griseofulvin common.

Tinea corporis (also known as ringworm, tinea circinata, and tinea glabrosa) is a superficial fungal infection (dermatophytosis) of the arms and legs, especially on glabrous skin; however, it may occur on any part of the body. It is similar to other forms of tinea.

The skin typically presents as red and hot. These infections can be painful.

Pus is usually present, along with gradual thickening and browning discoloration of the nail plate.

Tinea manuum (or tinea manus) is a fungal infection of the hand. It is typically more aggressive than tinea pedis but similar in look. Itching, burning, cracking, and scaling are observable and may be transmitted sexually or otherwise, whether or not symptoms are present. Alternatively, it may be caused by an allergic reaction, known as a "dermatophytid reaction". "For example, a fungal infection on the foot may cause an itchy, bumpy rash to appear on the fingers. These eruptions (dermatophytids, or identity or id reactions) are allergic reactions to the fungus. They do not result from touching the infected area. The eruptions may appear on many different areas of the body at once."

Tinea capitis (also known as "herpes tonsurans", "ringworm of the hair", "ringworm of the scalp", "scalp ringworm", and "tinea tonsurans") is a cutaneous fungal infection (dermatophytosis) of the scalp. The disease is primarily caused by dermatophytes in the "Trichophyton" and "Microsporum" genera that invade the hair shaft. The clinical presentation is typically single or multiple patches of hair loss, sometimes with a 'black dot' pattern (often with broken-off hairs), that may be accompanied by inflammation, scaling, pustules, and itching. Uncommon in adults, tinea capitis is predominantly seen in pre-pubertal children, more often boys than girls.

At least eight species of dermatophytes are associated with tinea capitis. Cases of "Trichophyton" infection predominate from Central America to the United States and in parts of Western Europe. Infections from "Microsporum" species are mainly in South America, Southern and Central Europe, Africa and the Middle East. The disease is infectious and can be transmitted by humans, animals, or objects that harbor the fungus. The fungus can also exist in a carrier state on the scalp, without clinical symptomatology. Treatment of tinea capitis requires an oral antifungal agent; griseofulvin is the most commonly used drug, but other newer antimycotic drugs, such as terbinafine, itraconazole, and fluconazole have started to gain acceptance.

Ulcerative dermatitis is a skin disorder in rodents associated with bacterial growth often initiated by self-trauma due to a possible allergic response. Although other organisms can be involved, bacteria culture frequently shows Staphylococcus aureus. Primarily found on the rib cage, neck, and shoulder, lesions are often irregular, circumscribed, and moist. Intense itching may lead to scratching which may aggravate and perpetuate the lesion. Destruction of the epidermis along with underlying pustules or abscesses, and granulomatous inflammation, may be present.

In cases where topical treatment alone does not resolve the dermatitis and irritants are not known, a secondary bacterial, fungal or yeast infection might be present and may require an anti-fungal or antibiotics to be prescribed by the veterinarian to affect a cure.

In rats, this skin disorder may be observed on the neck and head, often secondary to skin trauma from scratches or fighting.

As the common name for this condition implies, it causes itching or a burning sensation in the groin area, thigh skin folds or anus. It may involve the inner thighs and genital areas, as well as extending back to the perineum and perianal areas.

Affected areas may appear red, tan, or brown, with flaking, rippling, peeling or cracking skin.

The acute infection begins with an area in the groin fold about a half-inch across, usually on both sides. The area may enlarge, and other sores may develop. The rash has sharply defined borders that may blister and ooze.

Tinea cruris does have similar symptoms to Inverse psoriasis.

It may appear as thickened, scaly, and sometimes boggy swellings, or as expanding raised red rings (ringworm). Common symptoms are severe itching of the scalp, dandruff, and bald patches where the fungus has rooted itself in the skin. It often presents identically to dandruff or seborrheic dermatitis. The highest incidence in the United States of America is in American boys of school age.

There are three type of tinea capitis, microsporosis, trichophytosis, and favus; these are based on the causative microorganism, and the nature of the symptoms. In "microsporosis", the lesion is a small red papule around a hair shaft that later becomes scaly; eventually the hairs break off 1–3 mm above the scalp. This disease used to be caused primarily by "Microsporum audouinii", but in Europe, "M. canis" is more frequently the causative fungus. The source of this fungus is typically sick cats and kittens; it may be spread through person to person contact, or by sharing contaminated brushes and combs. In the United States, "Trichophytosis" is usually caused by "Trichophyton tonsurans", while "T. violaceum" is more common in Eastern Europe, Africa, and India. This fungus causes dry, non-inflammatory patches that tend to be angular in shape. When the hairs break off at the opening of the follicle, black dots remain. "Favus" is caused by "T. schoenleinii", and is endemic in South Africa and the Middle East. It is characterized by a number of yellowish, circular, cup-shaped crusts (scutula) grouped in patches like a piece of honeycomb, each about the size of a split pea, with a hair projecting in the center. These increase in size and become crusted over, so that the characteristic lesion can only be seen around the edge of the scab.

Infectious keratitis can be bacterial, fungal, viral, or protozoal. Remarkable differences in presentation of the patient allows presumptive diagnosis by the eye care professional, helping in institution of appropriate anti-infective therapy.