A stinging and burning sensation with rash is often felt and noticed, but itching is less common. Often the rash is steroid responsive, initially improving with application of topical steroid. The redness caused by perioral dermatitis has been associated with variable level of depression.

Initially, there may be small pinpoint papule either side of the nostrils. Multiple small (1-2mm) papules and pustules then occur around the mouth, nose and sometimes cheeks. The area of skin directly adjacent to the lips, also called the vermillion border, is spared and looks normal. There may be some mild background redness and occasional scale. These areas of skin are felt to be drier and therefore there is a tendency to moisturise them more frequently. Hence, they do not tolerate drying agents well and the rash can be worsened by them.

Perioral dermatitis is also known by other names including rosacea-like dermatoses, periorofacial dermatitis and periorificial dermatitis.

Unlike rosacea which involves mainly the nose and cheeks, there is no telangiectasia in perioral dermatitis. Rosacea also has a tendency to be present in older people. Acne can be distinguished by the presence of comedones and by its wider distribution on the face and chest. There are no comedones in personal dermatitis.

Other skin diseases which may resemble perioral dermatitis include:

- Rosacea

- Acne vulgaris

- Seborrheic dermatitis

- Allergic contact dermatitis

- Irritant contact dermatitis

Irritant diaper dermatitis is a generic term applied to skin rashes in the diaper area that are caused by various skin disorders and/or irritants.

Generic "diaper rash" or "irritant diaper dermatitis" (IDD) is characterized by joined patches of erythema and scaling mainly seen on the surfaces, with the skin folds spared.

Diaper dermatitis with secondary bacterial or fungal involvement tends to spread to surfaces (i.e. skin folds), as well as convex surfaces, and often exhibits a central red, beefy erythema with satellite pustules around the border.

It is usually considered a form of irritant contact dermatitis. The word "diaper" is in the name not because the diaper itself causes the rash but rather because the rash is associated with diaper use, being caused by the materials trapped by the diaper (usually feces). Allergic contact dermatitis has also been suggested, but there is little evidence for this cause. In adults with incontinence (fecal, urinary, or both), the rash is sometimes called incontinence-associated dermatitis (IAD).

The term diaper candidiasis is used when a fungal origin is identified. The distinction is critical because the treatment (antifungals) is completely different.

Discoid eczema (nummular eczema, exudative eczema, microbial eczema) is characterized by round spots of oozing or dry rash, with clear boundaries, often on lower legs. It is usually worse in winter. Cause is unknown, and the condition tends to come and go. (ICD-10 L30.0)

Venous eczema (gravitational eczema, stasis dermatitis, varicose eczema) occurs in people with impaired circulation, varicose veins, and edema, and is particularly common in the ankle area of people over 50. There is redness, scaling, darkening of the skin, and itching. The disorder predisposes to leg ulcers. (ICD-10 I83.1)

The diagnosis of IDD is made clinically, by observing the limitation of an erythematous eruption to the convex surfaces of the genital area and buttocks. If the diaper dermatitis occurs for greater than 3 days it may be colonized with "Candida albicans", giving it the beefy red, sharply marginated, appearance of diaper candidiasis.

Perioral dermatitis is a type of skin rash. Symptoms include multiple small (1–2 mm) bumps and blisters with sometimes background redness and scale, localized to the skin around the mouth and nostrils. Less commonly the eyes and genitalia may be involved. It can be persistent or recurring and resembles particularly rosacea and to some extent acne and allergic dermatitis. The term dermatitis is a misnomer because this is not an eczematous process.

The cause is unclear. Topical steroids are associated with the condition and moisturizers and cosmetics may contribute. The underlying mechanism may involve blockage of the skin surface followed by subsequent excessive growth of skin flora. Fluorinated toothpaste and some micro-organisms including candida may also worsen the condition, but their roles in this condition is unclear. It is considered a disease of the hair follicle with biopsy samples showing microscopic changes around the hair follicle. Diagnosis is based on symptoms.

Treatment is typically by stopping topical steroids, changing cosmetics, and in more severe cases, taking tetracyclines by mouth. Stopping steroids may initially worse the rash. The condition is estimated to affect 0.5-1% of people a year in the developed world. Up to 90% of those affected are women between the ages of 16 and 45 years, though it also affects children and the elderly, and has an increasing incidence in men.

Redness around the lips in circumoral distribution with dryness and scale is typical. Chapping may also occur, especially in cold weather.

Frequent, chronic contact of instruments to skin may make it callous by the thickening of stratum corneum. Use of 'thumb position' in cellists may cause callosity of left thumb. Garrod's pads are seen on the dorsal left second and third fingers over the proximal interphalangeal joints in violinists. Drummer's digit is the callosity seen on the lateral phalynx of the left finger. Callosities need treatment only when they are excessive or symptomatic.

Lip lickers dermatitis, popularly known as perioral dermatitis, is an Irritant contact dermatitis on and around the lips due to saliva from repetitive lip licking. Involving children more than adults, the resulting papules, scaling, erythema and occasional fissures and crusting make a well-defined ring around the lips. The rash extends as far as the tongue can reach and frequently spares the angle of the mouth. Unlike periorificial dermatitis, the vermillion border of the lip is often involved and the treatment is simple moisturisers.

The intense contact between a musical instrument and skin may exaggerate existing skin conditions or cause new skin skin conditions. Skin conditions like hyperhidrosis, lichen planus, psoriasis, eczema, and urticaria may be caused in instrumental musicians due to occupational exposure and stress. Allergic contact dermatitis and irritant contact dermatitis are the most common skin conditions seen in string musicians.

Contact dermatitis is a localized rash or irritation of the skin caused by contact with a foreign substance. Only the superficial regions of the skin are affected in contact dermatitis. Inflammation of the affected tissue is present in the epidermis (the outermost layer of skin) and the outer dermis (the layer beneath the epidermis).

Contact dermatitis results in large, burning, and itchy rashes. These can take anywhere from several days to weeks to heal. This differentiates it from contact urticaria (hives), in which a rash appears within minutes of exposure and then fades away within minutes to hours. Even after days, contact dermatitis fades only if the skin no longer comes in contact with the allergen or irritant. Chronic contact dermatitis can develop when the removal of the offending agent no longer provides expected relief.

Irritant dermatitis is usually confined to the area where the trigger actually touched the skin, whereas allergic dermatitis may be more widespread on the skin. Symptoms of both forms include the following:

- Red rash. This is the usual reaction. The rash appears immediately in irritant contact dermatitis; in allergic contact dermatitis, the rash sometimes does not appear until 24–72 hours after exposure to the allergen.

- Blisters or wheals. Blisters, wheals (welts), and urticaria (hives) often form in a pattern where skin was directly exposed to the allergen or irritant.

- Itchy, burning skin. Irritant contact dermatitis tends to be more painful than itchy, while allergic contact dermatitis often itches.

While either form of contact dermatitis can affect any part of the body, irritant contact dermatitis often affects the hands, which have been exposed by resting in or dipping into a container (sink, pail, tub, swimming pools with high chlorine) containing the irritant.

Lepidopterism is an irritant contact dermatitis caused by irritating caterpillar or moth hairs coming into contact with the skin or mucosa. When referring to the cause, moth dermatitis and caterpillar dermatitis are commonly used; Caripito itch (known as "papillonite" in French) is an older name referring to the moth dermatitis caused by some "Hylesia" species.

Eczema is another cause of chronic irritation and affects millions of individuals. Eczema simply means a dry skin which is itchy. The condition usually starts at an early age and continues throughout life. The major complaint of people who suffer from eczema is an itchy dry skin. Sometimes, the itching will be associated with a skin rash. The affected areas are always dry, scaly, reddish and may ooze sometimes. Eczema cannot be cured, but its symptoms can be controlled. One should use moisturizers, use cold compresses and avoid frequent hot showers. There are over the counter corticosteroids creams which can be applied. Sometimes, an anti histamine has to be used to prevent the chronic itching sensations. There are also many individuals who have allergies to a whole host of substances like nuts, hair, dander, plants and fabrics. For these individuals, even the minimal exposure can lead to a full blown skin rash, itching, wheezing and coughing. Unfortunately, other than avoidance, there is no other cure. There are allergy shots which can help desensitize against an allergen but often the results are poor and the treatments are expensive. Most of these individuals with chronic irritation from allergens usually need to take anti histamines or use a bronchodilator to relieve symptoms.

Another common irritation disorder in females is intertrigo. This disorder is associated with chronic irritation under folds of skin. This is typically seen under large breasts, groins and folds of the abdomen in obese individuals. Candida quickly grows in warm moist areas of these folds and presents as a chronic itch. Over time, the skin becomes red and often oozes.

Perspiration is also a chronic type of irritation which can be very annoying. Besides being socially unacceptable, sweat stain the clothes and can present with a foul odor. In some individuals, the warm moist areas often become easily infected. The best way to treat excess sweating is good hygiene, frequent change of clothes and use of deodorants/antiperspirants.

Bacterial skin infections include:

- Folliculitis is an infection of the hair follicle that can resemble pimples.

- Impetigo is a highly contagious bacterial skin infection most common among pre-school children. It is primarily caused by "Staphylococcus aureus", and sometimes by "Streptococcus pyogenes".

- Erysipelas is an acute streptococcus bacterial infection of the deep epidermis with lymphatic spread.

- Cellulitis is a diffuse inflammation of connective tissue with severe inflammation of dermal and subcutaneous layers of the skin. Cellulitis can be caused by normal skin flora or by exogenous bacteria, and often occurs where the skin has previously been broken: cracks in the skin, cuts, blisters, burns, insect bites, surgical wounds, intravenous drug injection or sites of intravenous catheter insertion. Skin on the face or lower legs is most commonly affected by this infection, though cellulitis can occur on any part of the body.

Contact dermatitis is a type of inflammation of the skin.

It results from either exposure to allergens (allergic contact dermatitis) or irritants (irritant contact dermatitis). Phototoxic dermatitis occurs when the allergen or irritant is activated by sunlight. Diagnosis of allergic contact dermatitis can often be supported by patch testing.

The symptoms of allergic contact dermatitis are very similar to the ones caused by irritant contact dermatitis, which makes the first even harder to diagnose. The first sign of allergic contact dermatitis is the presence of the rash or skin lesion at the site of exposure. Depending on the type of allergen causing it, the rash can ooze, drain or crust and it can become raw, scaled or thickened. Also, it is possible that the skin lesion does not take the form of a rash but it may include papules, blisters, vesicles or even a simple red area. The main difference between the rash caused by allergic contact dermatitis and the one caused by irritant contact dermatitis is that the latter tends to be confined to the area where the trigger touched the skin, whereas in allergic contact dermatitis the rash is more likely to be more widespread on the skin. Another characteristic of the allergic contact dermatitis rash is that it usually appears after a day or two after exposure to the allergen, unlike irritant contact dermatitis that appears immediately after the contact with the trigger.

Other symptoms may include itching, skin redness or inflammation, localized swelling and the area may become more tender or warmer. If left untreated, the skin may darken and become leathery and cracked. Pain can also be present.

The symptoms of allergic contact may persist for as long as one month before resolving completely. Once an individual has developed a skin reaction to a certain substance it is most likely that they will have it for the rest of their life, and the symptoms will reappear when in contact with the allergen.

Infection of the skin is distinguished from dermatitis, which is inflammation of the skin, but a skin infection can result in skin inflammation. Skin inflammation due to skin infection is called "infective dermatitis."

Bacterial skin infections affected about 155 million people and cellulitis occurred in about 600 million people in 2013.

Although there are a multitude of varying appearances, the id reaction often presents with symmetrical red patches of eczema with papules and vesicles, particularly on the outer sides of the arms, face and trunk which occur suddenly and are intensely itchy occur a few days to a week after the initial allergic or irritant dermatitis. Most commonly, athletes foot can lead to localised vesicles on hands, bacterial infections to erythema nodosum and herpes simplex virus to erythema multiforme.

The diagnosis is frequently made by treating the initial triggering skin problem and observing the improvement in the eczematous rash. Both the initial skin problem and the id reaction must be observed to make the diagnosis.

All dyshidrotic rashes are not id reactions, but id reactions are often dishydrotic-like.

Initial tests may include isolating a fungus by taking a swab and sending it for culture. Patch testing may be considered if there is suspicion of allergic contact dermatitis.

A skin biopsy is rarely necessary, but if done mostly shows an interstitial granulomatous dermatitis, some lesions being spongiotic. Id reactions cannot be distinguished from other skin diseases by histopathology. However, they can be distinguished from other id reactions by histopathology.

Acneiform eruptions are a group of dermatoses including acne vulgaris, rosacea, folliculitis, and perioral dermatitis. Restated, acneiform eruptions are follicular eruptions characterized by papules and pustules resembling acne.

The hybrid term "acneiform", literally, refers to an appearance similar to acne.

The terminology used in this field can be complex, and occasionally contradictory. Some sources consider acne vulgaris part of the differential diagnosis for an acneiform eruption. Other sources classified acne vulgaris under acneiform eruption. MeSH explicitly excludes perioral dermatitis from the category of "acneiform eruptions", though it does group acneiform eruptions and perioral dermatitis together under "facial dermatoses".

Main symptoms that occur when affected with Tinea Barbae is pimple or blister amongst affected area, swelling and redness around infected area, red and lumpy skin on infected area. Crusting around hairs in infected area will occur, hairs on infected area will also be effortless to pull out. Tinea Barbae can be itchy or painful to touch but these symptoms do not always occur.

Causes include infection with dermatophytosis, Mycobacterium, viruses, bacteria and parasites. Eczematous conditions including contact allergic dermatitis and stasis dermatitis as well as stitches and trauma have also been associated with id reactions. Radiation treatment of tinea capitis has been reported as triggering an id reaction.

Tinea barbæ (also known as "Barber's itch," "Ringworm of the beard," and "Tinea sycosis") is a fungal infection of the hair. Tinea barbae is due to a dermatophytic infection around the bearded area of men. Generally, the infection occurs as a follicular inflammation, or as a cutaneous granulomatous lesion, i.e. a chronic inflammatory reaction. It is one of the causes of Folliculitis. It is most common among agricultural workers, as the transmission is more common from animal-to-human than human-to-human. The most common causes are "Trichophyton mentagrophytes" and "T. verrucosum".

Uranium dermatosis is a cutaneous condition characterized by an irritant contact dermatitis and skin burns due to exposure to uranium.

Irritant folliculitis is a cutaneous condition and usually occurs following the application of topical medications.

Tulip fingers are a cutaneous condition, a combined allergic and irritant contact dermatitis caused by contact with tulip bulbs.