Signs include facial redness, small and superficial dilated blood vessels on facial skin, papules, pustules, and swelling.

In glandular rosacea, men with thick sebaceous skin predominate, a disease in which the papules are edematous, the pustules often 0.5 to 1.0 cm in size, with nodulocystic lesions often present.

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".

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

A papulopustular condition is a condition composed of both papule and pustules.

Examples of papulopustular conditions include:

- Papulopustular rosacea

- Papulopustular acne

- Sycosis

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.

Gram-negative rosacea is a cutaneous condition that clinically looks like stage II or III rosacea.

A skin and skin structure infection (SSSI), also referred to as skin and soft tissue infection (SSTI) or acute bacterial skin and skin structure infection (ABSSSI), is an infection of skin and associated soft tissues (such as loose connective tissue and mucous membranes). The pathogen involved is usually a bacterial species. Such infections often requires treatment by antibiotics.

Until 2008, two types were recognized, complicated skin and skin structure infection (cSSSI) and uncomplicated skin and skin structure infection (uSSSI). "Uncomplicated" SSSIs included simple abscesses, impetiginous lesions, furuncles, and cellulitis. "Complicated" SSSIs included infections either involving deeper soft tissue or requiring significant surgical intervention, such as infected ulcers, burns, and major abscesses or a significant underlying disease state that complicates the response to treatment. Superficial infections or abscesses in an anatomical site, such as the rectal area, where the risk of anaerobic or gram-negative pathogen involvement is higher, should be considered complicated infections. The two categories had different regulatory approval requirements. The uncomplicated category (uSSSI) is normally only caused by "Staphylococcus aureus" and "Streptococcus pyogenes", whereas the complicated category (cSSSI) might also be caused by a number of other pathogens. In cSSSI, the pathogen is known in only about 40% of cases.

Because cSSSIs are usually serious infections, physicians do not have the time for a culture to identify the pathogen, so most cases are treated empirically, by choosing an antibiotic agent based on symptoms and seeing if it works. For less severe infections, microbiologic evaluation via tissue culture has been demonstrated to have high utility in guiding management decisions. To achieve efficacy, physicians use broad-spectrum antibiotics. This practice contributes in part to the growing incidence of antibiotic resistance, a trend exacerbated by the widespread use of antibiotics in medicine in general. The increased prevalence of antibiotic resistance is most evident in methicillin-resistant "Staphylococcus aureus" (MRSA). This species is commonly involved in cSSSIs, worsening their prognosis, and limiting the treatments available to physicians. Drug development in infectious disease seeks to produce new agents that can treat MRSA.

Since 2008, the U.S. Food and Drug Administration has changed the terminology to "acute bacterial skin and skin structure infections" (ABSSSI). The Infectious Diseases Society of America (IDSA) has retained the term "skin and soft tissue infection".

It is commonly misdiagnosed as chickenpox or rosacea. Pleva is also often misidentified as a form of staph. The most accurate way to diagnose it is by biopsy. This disease has not been known to be life-threatening. However, there may be mutations of the disease that can cause ulcers on the exterior.

The primary skin lesion usually starts with a macule that is painless, round and erythematous. Then, it develops into a pustule, and then a bulla with central hemorrhagic focus. The bullae progresses into an ulcer which extends laterally. Finally it becomes a gangrenous ulcer with central black eschar surrounded by erythematous halo.

The lesion may be single or multiple. They are most commonly seen in perineum and under arm pit. However, it can occur in any part of the body.

Gram-negative folliculitis occurs in patients who have had moderately inflammatory acne for long periods and have been treated with long-term antibiotics, mainly tetracyclines, a disease in which cultures of lesions usually reveals a species of "Klebsiella", "Escherichia coli", "Enterobacter", or, from the deep cystic lesions, "Proteus".

Ocular rosacea is a manifestation of rosacea that affects the eyes and eyelids. Signs and symptoms generally consist of redness, irritation or burning of the eyes. Affected individuals may also feel that there is something, such as an eyelash, in the eye and frequently have redness of the nose and cheeks as well.

Those who suffer from ocular rosacea may be treated with warm compresses, artificial tears and washing the area around the eye with warm water, including the eyelids, to help relieve symptoms. Additionally, oral antibiotics, typically doxycycline, may be prescribed. Some people with ocular rosacea feel that dietary restrictions of caffeine, spicy foods, and alcoholic beverages may reduce or eliminate symptoms.

Ecthyma gangrenosum is a type of skin lesion characterized by vesicles or blisters which rapidly evolve into pustules and necrotic ulcers with undermined tender erythematous border. "Ecthyma" means a pus forming infection of the skin with an ulcer, "gangrenosum" means the gangrene or necrosis. It is the pathognomonic of "Pseudomonas aeruginosa" bacteremia. "Pseudomonas aeruginosa" is a gram negative, aerobic, coccobacillus bacterium.

This type of skin lesion was first described in association with "Pseudomonas aeruginosa" by L. Barker in 1897. It was given the name "ecthyma gangrenosum" by Hitschmann and Kreibich.

It mostly occurs in patients with underlying immunocompromised conditions (e.g. Malignancy). Although most cases are found in "Pseudomonas aeruginosa" infection, there are recent reports of this skin lesion associated with other microorganisms, such as "Escherichia coli, Citrobacter freundii, Klebsiella pneumonia", various other Pseudomonas species, and "Morganella morganii."

Blepharitis is characterized by chronic inflammation of the eyelid, usually at the base of the eyelashes. Symptoms include inflammation, irritation, itchiness, a burning sensation, excessive tearing, and crusting and sticking of eyelids. Additional symptoms may include visual impairment such as photophobia and blurred vision. Symptoms are generally worse in the mornings and patients may experience exacerbation and several remissions if left untreated. It is typically caused by bacterial infection or blockage of the meibomian oil glands. Diseases and conditions that may lead to blepharitis include: rosacea, herpes simplex dermatitis, varicella-zoster dermatitis, molluscum contagiosum, allergic dermatitis, contact dermatitis, seborrheic dermatitis, staphylococcal dermatitis, demodicosis (Demodex), and parasitic infections ("e.g.", Demodex and Phthiriasis palpebrarum).

The parasite, "Demodex folliculorum" ("D. folliculorum"), causes blepharitis when the parasite is present in excessive numbers within the dermis of the eyelids. These parasites can live for approximately 15 days. The parasites (both adult and eggs) live on the hair follicle, inhabiting the sebaceous and apocrine gland of the human lid. Direct contact allows this pathogen to spread. Factors that allow this pathogen to multiply include hypervascular tissue, poor hygienic conditions, and immune deficiency. In treating Blepharitis caused by "D. folliculorum", mechanical cleaning and proper hygiene are important towards decreasing the parasites numbers.

Associated Symptoms:

- Watery eyes - due to excessive tearing.

- Red eyes - due to dilated blood vessels on the sclera.

- Swollen eyelids - due to inflammation.

- Crusting at the eyelid margins/base of the eyelashes/medial canthus, generally worse on waking - due to excessive bacterial buildup along the lid margins.

- Eyelid sticking - due to crusting along the eyelid margin.

- Eyelid itching - due to the irritation from inflammation and epidermis scaling of the eyelid.

- Flaking of skin on eyelids - due to tear film suppressed by clog meibomian glands.

- Gritty/burning sensation in the eye, or foreign-body sensation - due to crusting from bacteria and clogged oil glands

- Frequent blinking - due to impaired tear film from clogged oil glands unable to keep tears from evaporating.

- Light sensitivity/photophobia

- Misdirected eyelashes that grow abnormally - due to permanent damage to the eyelid margin

- Eyelash loss - due to excessive buildup of bacteria along the base of the eyelashes.

- Infection of the eyelash follicle/sebaceous gland (hordeolum)

- Debris in the tear film, seen under magnification (improved contrast with use of fluorescein drops)

Chronic blepharitis may result in damage of varying severity and, in the worst cases, may have a negative effect on vision. This can be resolved with a proper eyeglass prescription. Long-term untreated blepharitis can lead to eyelid scarring, excess tearing, difficulty wearing contact lenses, development of a stye (an infection near the base of the eyelashes, resulting in a painful lump on the edge of the eyelid) or a chalazion (a blockage/bacteria infection in a small oil glands at the margin of the eyelid, just behind the eyelashes, leading to a red, swollen eyelid), chronic pink eye (conjunctivitis), keratitis, and corneal ulcer or irritation. The lids may become red and may have ulcerate, non-healing areas that may lead to bleeding. Blepharitis can also cause blurred vision due to a poor tear film. Tears may be frothy or bubbly, which can contribute to mild scarring along the eyelids. Symptoms and signs of blepharitis are often erroneously ascribed by the patient as "recurrent conjunctivitis".

Staphylococcal blepharitis and Posterior blepharitis or "rosacea-associated" blepharitis Symptoms

Symptoms include a foreign body sensation, matting of the lashes, and burning. Collarette around eyelashes, a ring-like formation around the lash shaft, can be observed. Other symptoms include loss of eyelashes or broken eyelashes. The condition can sometimes lead to a chalazion or a stye. Chronic bacterial blepharitis may also lead to ectropion. Posterior blepharitis or "rosacea-associated" blepharitis is manifested by a broad spectrum of symptoms involving the lids including inflammation and plugging of the meibomian orifices and production of abnormal secretion upon pressure over the glands.

Gram-negative toe web infection is a cutaneous condition that often begins with dermatophytosis.

Rhinoscleroma has been divided into 3 stages: catarrhal/atrophic, granulomatous, and sclerotic stages. The catarrhal stage begins with a nonspecific rhinitis, which progresses into purulent, fetid rhinorrhea, and crusting, which can last for weeks or even months. The granulomatous stage results in the development of a bluish red nasal mucosa and the development of intranasal rubbery nodules or polyps. Nose bleeds, nasal deformity, and destruction of the nasal cartilage are also noted (Hebra nose). The damage may result in anesthesia of the soft palate, enlargement of the uvula, dysphonia, and various degrees of airway obstruction. The fibrotic stage is characterized by sclerosis and fibrosis. Lymphadenitis is absent.

Blepharitis ( ) is one of the most common ocular conditions characterized by inflammation, scaling, reddening, and crusting of the eyelid. This condition may also cause burning, itching, or a grainy sensation when introducing foreign objects or substances to the eye. Although blepharitis is not sight-threatening, it can lead to permanent alterations of the eyelid margin. The overall etiology is a result of bacteria and inflammation from congested meibomian oil glands at the base of each eyelash. Other conditions may give rise to blepharitis, whether they be infectious or noninfectious, including, but not limited to, bacterial infections or allergies.

Different variations of blepharitis can be classified as seborrheic, staphylococcal, mixed, posterior or meibomitis, or parasitic. In a survey of US ophthalmologists and optometrists, 37% to 47% of patients seen by those surveyed had signs of blepharitis, which can affect all ages and ethnic groups. One single-center study of 90 patients with chronic blepharitis found that the average age of patients was 50 years old.

The infections that frequently involve anaerobic bacteria include superficial infections, including infected paronychia, infected human or animal bites, cutaneous ulcers, cellulitis, pyoderma, and hidradenitis suppurativa. Secondary infected sites include secondary infected diaper rash, gastrostomy or tracheostomy site wounds, scabies or kerion infections, eczema, psoriasis, poison ivy, atopic dermatitis, eczema herpeticum, infected subcutaneous sebaceous or inclusion cysts, and postsurgical wound infection.

Skin involvement in subcutaneous tissue infections includes: cutaneous and subcutaneous abscesses, breast abscess, decubitus ulcers, infected pilonidal cyst or sinus, Meleney's ulcer infected diabetic (vascular or trophic) ulcers, bite wound, anaerobic cellulitis and gas gangrene, bacterial synergistic gangrene, and burn wound infection. Deeper anaerobic soft-tissue infections are necrotizing fasciitis, necrotizing synergistic cellulitis, gas gangrene and crepitus cellulitis. These can involve the fascia as well as the muscle surrounded by the fascia, and may also induce myositis and myonecrosis.

The isolates found in soft-tissue infections can vary depending on the type of infection. The infection's location and the circumstances causing the infection can also influence the nature of the microorganisms recovered. Bacteria that are members of the 'normal flora' of the region of the infection are often also isolated from lesions involving anaerobic bacteria.

Specimens obtained from wounds and subcutaneous tissue infections and abscesses in the rectal area (perirectal abscess, decubitus ulcer) or that are of gut flora origin(i.e. diabetic foot infection) often to yield colonic flora organisms. These are generally "B. fragilis" group, "Clostridium" spp., Enterobacteriaceae and "Enterococcus" spp. On the other hand, infections in and around the oropharynx, or infections that originate from that location, frequently contain oral flora organisms (i.e. paronychia, bites, breast abscess). These bacteria include pigmented "Prevotella" and "Porphyromonas, Fusobacterium" and Peptostreptococcus spp. Skin flora organisms such as "S. aureus" and "Streptococcus" spp., or nosocomially acquired microorganisms can be recovered at all body locations. Human bite infections often contain "Eikenella" spp. and animal bites harbor "Pasteurella multocida" in addition to oral flora,

Anaerobes infections are often polymicrobial in nature, and sometimes (i.e. decubitus ulcers, diabetic foot ulcer) they are complicated by bacteremia and or osteomyelitis . Infections which are in the deep tissues ( necrotizing cellulitis, fasciitis and myositis) often include "Clostridium" spp., "S. pyogenes" or polymicrobic combinations of both aerobic and anaerobic bacteria. Gas in the tissues and putrid-like pus with a gray thin quality are often found in these infections, and they are frequently associated with a bacteremia and high mortality rate.

Treatment of deep-seated soft-tissue infections includes: vigorous surgical management that includes surgical debridement and drainage. Even though there are no controlle studies that support this approach improvement of the involved tissues oxygenation by enhancement of blood supply and administration of hyperbaric oxygen, especially in clostridial infection, may be helpful.

Malakoplakia or malacoplakia (from Greek "Malako" "soft" + "Plako" "plaque") is a rare inflammatory condition which makes its presence known as a papule, plaque or ulceration that usually affects the genitourinary tract. However, it may also be associated with other bodily organs. It was initially described in the early 20th century as soft yellowish plaques found on the mucosa of the urinary bladder. Microscopically it is characterized by the presence of foamy histiocytes with basophilic inclusions called Michaelis–Gutmann bodies.

It usually involves gram-negative bacteria.

The disease is characterised by the formation of painful abscesses in the mouth, lungs, breast, or gastrointestinal tract. Actinomycosis abscesses grow larger as the disease progresses, often over months. In severe cases, they may penetrate the surrounding bone and muscle to the skin, where they break open and leak large amounts of pus, which often contains characteristic granules (sulfur granules) filled with progeny bacteria. These granules are named due to their appearance, but are not actually composed of sulfur.

Anaerobes can be isolated from most types of upper respiratory tract and head and neck and infection and are especially common in chronic ones. These include tonsillar, peritonsillar and retropharyngeal abscesses, chronic otitis media, sinusitis and mastoiditis, eye ocular) infections, all deep neck space infections, parotitis, sialadenitis, thyroiditis, odontogenic infections, and postsurgical and nonsurgical head and neck wounds and abscesses., The predominant organisms are of oropharyngeal flora origin and include AGNB, "Fusobacterium" and Peptostreptococcus spp.

Anaerobes involve almost all dental infections. These include dental abscesses, endodontal pulpitis and periodontal (gingivitis and periodontitis) infections, and perimandibular space infection. Pulpitis can lead to abscess formation and eventually spread to the mandible and other neck spaces. In addition to strict anaerobic bacteria, microaerophilic streptococci and "Streptococcus salivarius" can also be present.

"Fusobacterium" spp. and anaerobic spirochetes are often the cause of acute necrotizing ulcerative gingivitis (or Vincent's angina) which is a distinct form of ulcerative gingivitis.

Deep neck infections that develop as a consequence of oral, dental and pharyngeal infections are generally polymicrobial in nature. These include extension of retropharyngeal cellulitis or abscess, mediastinitis following esophagus perforation, and dental or periodontal abscess.

There is no known cause of this disease; There is some evidence associating it with Parvovirus B19.

Rhinophyma is characterised by prominent pores and a fibrous thickening of the nose, sometimes with papules. It is associated with the common skin condition rosacea. It can carry a strong psychological impact due to its effect on one's personal appearance.

Rhinophyma is a slowly progressive condition due to hypertrophy of the sebaceous glands of the tip of the nose often seen in cases of long-standing acne rosacea; it is not a neoplasm. It presents as a pink, lobulated mass over the nose with superficial vascular dilation; it mostly affects men past middle age. Patients seek advice because of the perceived unsightly appearance of the enlargement, or obstruction in breathing and vision.

Infectious bovine keratoconjunctivitis, or IBK, is a veterinary infection of cattle caused by "Moraxella bovis", a Gram-negative, β-haemolytic, aerobic, rod-shaped bacterium. It is spread by direct contact or by flies serving as vectors. It is the most common ocular disease of cattle (mostly beef). IBK is similar to human pink eye and causes severe infection of the conjunctiva, edema, corneal opacity, and ulceration. This disease is highly contagious and occurs worldwide. Younger animals are more susceptible, but recovery with minimal damage is usual, if they are treated early. The disease is also known as pinkeye, New Forest eye or blight.