The prevalence and incidence of Grover's disease have not been firmly established. In a study from Switzerland, Grover's disease was diagnosed in just 24 of more than 30,000 skin biopsies [4]. Grover's disease is mainly seen in males over the age of forty.

Grover's disease affects chiefly white adults in the fifth decade or later, and appears to be around 1.6 to 2.1 times more common in men than in women. Grover's disease appears less commonly in darker-skinned individuals.

The cause of Grover's disease is unknown. Suspected triggers of disease activity include heat and sweating, sunlight, and adverse reaction to medications as well as ionizing radiation, end-stage renal disease/hemodialysis, and mechanical irritation or prolonged bed rest.

Some cases of Grover's disease have been associated with medications such as sulfadoxine-pyrimethamine, ribavirin, cetuximab, and interleukin-4 [1,8-15]. One series of 300 patients with Grover's disease reported an association with other coexisting dermatoses including atopic dermatitis, contact dermatitis, and xerosis cutis. Finally, smaller series have detailed an association with pyoderma gangrenosum, bacterial and viral infections, and occasionally, malignancies.

Pemphigus foliaceus has been recognized in pet dogs, cats, and horses and is the most common autoimmune skin disease diagnosed in veterinary medicine. Pemphigus foliaceus in animals produces clusters of small vesicles that quickly evolve into pustules. Pustules may rupture, forming erosions or become crusted. Left untreated, pemphigus foliaceus in animals is life-threatening, leading to not only loss of condition but also secondary infection.

Pemphigus vulgaris is a very rare disorder described in pet dogs and cats. Paraneoplastic pemphigus has been identified in pet dogs.

Many other conditions can lead to localized scaling or hyperpigmentation.

This condition should firmly be distinguished from dermatitis artefacta, which is the "factitious" creation of a skin lesion, whereas dermatosis neglecta results from unconscious avoidance of cleaning due to pain or immobility.

Other skin conditions which should not be mistaken for dermatosis neglecta include: terra firma-forme dermatosis (in which there is no history of inadequate cleaning); confluent and reticulated papillomatosis of Gougerot and Carteaud; several forms of ichthyosis; acanthosis nigricans; and Vagabond's disease.

DPN is not a premalignant condition nor is it associated with any underlying systemic disease. DPN lesions show no tendency to regress spontaneously, and often increase in size and number as an individual ages.

Dermatosis neglecta is a skin condition in which accumulation of sebum, keratin, sweat, dirt and debris leads to a localized patch of skin discoloration or a wart-like plaque. It is caused by inadequate hygiene of a certain body part, usually due to some form of disability or a condition that is associated with pain or increased sensitivity to touch (hyperesthesia) or immobility.

Dermatosis neglecta typically develops several months after a disability or other affliction leads to improper cleaning. Patients may deny that negligence is the cause of the lesion, even though it completely resolves on vigorous rubbing with alcohol swabs or water and soap (which provides both diagnosis and treatment). Recognizing the diagnosis avoids unnecessary skin biopsies.

Examples of case reports from the literature include a man who avoided washing the skin area surrounding an artificial pacemaker out of fear it might be damaged; a woman who didn't clean the right side of her chest due to hyperesthesia following an amputation for breast cancer (mastectomy); a girl who was afraid to wash the area around an abdominal scar; and a man with multiple fractures, shoulder dislocation and radial nerve palsy which significantly reduced his mobility.

Pityriasis lichenoides chronica (PLC) is probably caused by a hypersensitivity reaction to infectious agents such as the Epstein–Barr virus. Other infectious agents include the adenovirus and Parvovirus B19.

In 2016, interferon gamma/CXCL10 axis was hypothesized to be a target for treatments that reverse inflammation. Apremilast is undergoing investigation as a potential treatment .

Schamberg's disease is caused by leaky blood vessels near the surface of the skin, capillaries, which allow red blood cells to slip through into the skin. The red blood cells in the skin then fall apart and release their iron, which is released from hemoglobin. The iron causes a rust color and this accounts for the orange tint of the rash that can be seen on the skin. The underlying cause of the leaky blood vessels is not known, but researchers are suggesting that there could be some potential triggers. Some possible triggers include viral infection, a hypersensitivity to some agent, and interaction of some medications, such as thiamine and aspirin. Even though there is no correlation with genetics, there have been a few cases where few people in a family had this condition.

Although the cause of capillary inflammation is unknown, certain preventive measures can be taken. Doctors may prescribe medications that enhance the circulation of blood, which can keep blood vessels strong and healthy. Daily intake of vitamin C has proven to be a natural home remedy that can prevent the onsite of any disease or infection. Doctors always recommend that their patients monitor what they eat because their diet could be a possible factor that contributes to this condition. A healthy body that receives nutritious meals is more likely to have a healthy life that does not revolve around a lot of health problems.

Pityriasis lichenoides chronica is an uncommon, idiopathic, acquired dermatosis, characterized by evolving groups of erythematous, scaly papules that may persist for months.

Schamberg's disease, (also known as "progressive pigmentary dermatosis of Schamberg", "purpura pigmentosa progressiva" (PPP), and "Schamberg's purpura") is a chronic discoloration of the skin found in people of all ages, usually affecting the legs. It slowly spreads throughout the body, and is most common in males. It is named after Jay Frank Schamberg, who described it in 1901. There is no known cure for this disease and it is not a life-threatening condition. The skin lesions may cause itching, which can be treated by applying cortisone cream. The cortisone cream will only help with the itching and the discoloration of the skin will remain, which may cause a cosmetic concern in the future. Schamberg's disease is usually asymptomatic meaning that it shows no signs of this condition, except for the discoloration of the skin. This condition is caused by leaky blood vessels, where red blood cells escape near the surface of skin and release its iron into the surrounding tissue. The cause of the leaky capillaries is unknown.

In contrast to cutaneous LP, which is self limited, lichen planus lesions in the mouth may persist for many years, and tend to be difficult to treat, with relapses being common. Atrophic/erosive lichen planus is associated with a small risk of cancerous transformation, and so people with OLP tend to be monitored closely over time to detect any potential change early. Sometimes OLP can become secondarily infected with Candida organisms.

Erosive pustular dermatitis of the scalp (also known as "Erosive pustular dermatosis of the scalp") presents with pustules, erosions, and crusts on the scalp of primarily older Caucasean females, and on biopsy, has a lymphoplasmacytic infiltrate with or without foreign body giant cells and pilosebaceous atrophy.

Linear IgA bullous dermatosis is frequently associated with medication exposure, especially vancomycin, with men and women being equally affected. It was first described by Tadeusz Chorzelski in 1979. Linear IgA dermatosis is a rare immune-mediated blistering skin disease that may be divided into two types:

- "Adult linear IgA disease" is an acquired, autoimmune blistering disease that may present with a clinical pattern of vesicles indistinguishable from dermatitis herpetiformis, or with vesicles and bullae in a bullous pemphigoid-like appearance. This disease can often be difficult to treat even with usually effective medications such as rituximab.

- "Childhood linear IgA disease" (also known as "Chronic bullous disease of childhood") is an acquired, self-limited bullous disease that may begin by the time the patient is age 2 to 3 and usually remits by age 13.

DPN affects up to 35% of the African American population in the USA Insufficient data is available on the international frequency of DPN.

Lesions generally emerge during puberty, increasing steadily in number and size as an individual ages.

Black people with a fair complexion have the lowest frequency of involvement. DPN also occurs among Asians, although the exact incidence is unknown. Females are affected more frequently than males. Dermatosis papulosa nigra generally emerges in adolescence and is rarely in persons younger than 7 years The incidence, size and number of lesions of DPN increases with age.

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

Sometimes, the skin will blister when it comes into contact with a cosmetic, detergent, solvent, or other chemical such as nickel sulfate, Balsam of Peru, or urushiol (poison ivy, poison oak, poison sumac). This is known as contact dermatitis. Blisters can also develop as a result of an allergic reaction to an insect bite or sting. Some chemical warfare agents, known as blister agents or vesicants, cause large, painful blisters wherever they contact skin; an example is mustard gas.

Lichen striatus (also known as blaschko linear acquired inflammatory skin eruption and linear lichenoid dermatosis) is a rare skin condition that is seen primarily in children, most frequently appearing ages 5–15. It consists of a self-limiting eruption of small, scaly papules.

Exogenous ochronosis can be caused from long-term usage of certain "skin lightening" products, even if the hydroquinone is in amounts as small as 2%.

Skin lightening products are still prevalent in many parts of the world. This may be due to aesthetic or social standing reasons, in areas where a lighter skin tone is considered to be a sign of wealth or beauty.

As well, skin-lightening creams containing compounds such as hydroquinone are commonly used to help with hyperpigmentation disorders such as melasma.

Hydroquinone is the compound most frequently used in skin whitening products. Due to concerns about its side effects, it was almost banned by the FDA in 2006, as there were medical issues of carcinogenicity and reports of disfiguring ochronosis. In the European Union hydroquinone has been banned in cosmetic creams since 2000.

Long-term use of creams containing this compound may lead to exogenous ochronotic lesions. The duration of the use is directly proportional to the risk of developing the condition with most cases being after years of use.

Around 10–15 million skin lightening products are sold annually, with Japan being the major buyer.

The signs of sebaceous adenitis are caused by an inflammatory disease process which affects the sebaceous glands of the skin. The cause of the inflammatory disease is unknown. Different breeds of dogs may have different underlying causes of the disease.

Research is currently underway to find if there is a genetic predisposition for sebaceous adenitis; the exact mode of inheritance remains unknown.

In Standard Poodles, sebaceous adenitis is most likely an autosomal recessive inherited disease, with variable expression.

Erythema dyschromicum perstans (EDP) (also known as ashy dermatosis, and dermatosis cinecienta) is an uncommon skin condition with peak age of onset being young adults, but it may also be seen in children or adults of any age. EDP is characterized by hyperpigmented macules that are ash-grey in color and may vary in size and shape. While agents such as certain medications, radiographic contrast, pesticides, infection with parasites, and HIV have been implicated in the occurrence of this disease, the cause of this skin disease remains unknown.

EDP initially presents as grey or blue-brown circumferential or irregularly shaped macules or patches that appear. While the lesions of EDP are generally non-elevated, they may initially have a slight raised red margin as they first begin to appear. These lesions usually arise in a symmetric distribution and involve the trunk, but also commonly spread to the face and extremities. EDP does not usually have symptoms beside the macules and patches of discolored skin; however, some itching in these areas may occur.

Because EDP is an uncommon disease of the skin, it is important to consider other skin diseases that may resemble erythema dyschromicum perstans, such as infectious diseases (i.e. leprosy or pinta), reaction to drugs, post inflammatory hyperpigmentation, or lichen planus pigmentosus.

There is no cure for EDP. While multiple various topical and systemic therapies have been tried, none have been consistently successful. In children, spontaneous resolution of EDP over the course of months to years is possible; however, this outcome is less likely if EDP presents in adulthood.

Small plaque parapsoriasis (also known as chronic superficial dermatitis) characteristically occurs with skin lesions that are round, oval, discrete patches or thin plaques, mainly on the trunk.

Subtypes:

- "Xanthoerythrodermia perstans" is a distinct variant with lesions that are yellow in color.

- "Digitate dermatosis" is a distinct variant of with lesions in the shape of a finger and distributed symmetrically on the flanks.

Dermatitis herpetiformis generally responds well to medication and changes in diet. However, it is an autoimmune disease, and patients with DH are more likely than others to have thyroid problems and intestinal lymphoma.

Dermatitis herpetiformis does not usually cause complications on its own, without being associated with another condition. Complications from this condition, however, arise from the autoimmune character of the disease, as an overreacting immune system is a sign that something does not work well and might cause problems to other parts of the body that do not necessarily involve the digestive system.

Gluten intolerance and the body's reaction to it make the disease more worrying in what concerns the possible complications. This means that complications that may arise from dermatitis herpetiformis are the same as those resulting from coeliac disease, which include osteoporosis, certain kinds of gut cancer, and an increased risk of other autoimmune diseases such as thyroid disease.

The risks of developing complications from dermatitis herpetiformis decrease significantly if the affected individuals follow a gluten-free diet. The disease has been associated with autoimmune thyroid disease, insulin-dependent diabetes, lupus erythematosus, Sjögren's syndrome, sarcoidosis, vitiligo, and alopecia areata.

Many conditions affect the human integumentary system—the organ system covering the entire surface of the body and composed of skin, hair, nails, and related muscle and glands. The major function of this system is as a barrier against the external environment. The skin weighs an average of four kilograms, covers an area of two square meters, and is made of three distinct layers: the epidermis, dermis, and subcutaneous tissue. The two main types of human skin are: glabrous skin, the hairless skin on the palms and soles (also referred to as the "palmoplantar" surfaces), and hair-bearing skin. Within the latter type, the hairs occur in structures called pilosebaceous units, each with hair follicle, sebaceous gland, and associated arrector pili muscle. In the embryo, the epidermis, hair, and glands form from the ectoderm, which is chemically influenced by the underlying mesoderm that forms the dermis and subcutaneous tissues.

The epidermis is the most superficial layer of skin, a squamous epithelium with several strata: the stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, and stratum basale. Nourishment is provided to these layers by diffusion from the dermis, since the epidermis is without direct blood supply. The epidermis contains four cell types: keratinocytes, melanocytes, Langerhans cells, and Merkel cells. Of these, keratinocytes are the major component, constituting roughly 95 percent of the epidermis. This stratified squamous epithelium is maintained by cell division within the stratum basale, in which differentiating cells slowly displace outwards through the stratum spinosum to the stratum corneum, where cells are continually shed from the surface. In normal skin, the rate of production equals the rate of loss; about two weeks are needed for a cell to migrate from the basal cell layer to the top of the granular cell layer, and an additional two weeks to cross the stratum corneum.

The dermis is the layer of skin between the epidermis and subcutaneous tissue, and comprises two sections, the papillary dermis and the reticular dermis. The superficial papillary dermis with the overlying rete ridges of the epidermis, between which the two layers interact through the basement membrane zone. Structural components of the dermis are collagen, elastic fibers, and ground substance. Within these components are the pilosebaceous units, arrector pili muscles, and the eccrine and apocrine glands. The dermis contains two vascular networks that run parallel to the skin surface—one superficial and one deep plexus—which are connected by vertical communicating vessels. The function of blood vessels within the dermis is fourfold: to supply nutrition, to regulate temperature, to modulate inflammation, and to participate in wound healing.

The subcutaneous tissue is a layer of fat between the dermis and underlying fascia. This tissue may be further divided into two components, the actual fatty layer, or panniculus adiposus, and a deeper vestigial layer of muscle, the panniculus carnosus. The main cellular component of this tissue is the adipocyte, or fat cell. The structure of this tissue is composed of septal (i.e. linear strands) and lobular compartments, which differ in microscopic appearance. Functionally, the subcutaneous fat insulates the body, absorbs trauma, and serves as a reserve energy source.

Conditions of the human integumentary system constitute a broad spectrum of diseases, also known as dermatoses, as well as many nonpathologic states (like, in certain circumstances, melanonychia and racquet nails). While only a small number of skin diseases account for most visits to the physician, thousands of skin conditions have been described. Classification of these conditions often presents many nosological challenges, since underlying etiologies and pathogenetics are often not known. Therefore, most current textbooks present a classification based on location (for example, conditions of the mucous membrane), morphology (chronic blistering conditions), etiology (skin conditions resulting from physical factors), and so on. Clinically, the diagnosis of any particular skin condition is made by gathering pertinent information regarding the presenting skin lesion(s), including the location (such as arms, head, legs), symptoms (pruritus, pain), duration (acute or chronic), arrangement (solitary, generalized, annular, linear), morphology (macules, papules, vesicles), and color (red, blue, brown, black, white, yellow). Diagnosis of many conditions often also requires a skin biopsy which yields histologic information that can be correlated with the clinical presentation and any laboratory data.

There are also a number of medical conditions that cause blisters. The most common are chickenpox, herpes, impetigo, and a form of eczema called dyshidrosis. Other, much rarer conditions that cause blisters include:

- Bullous pemphigoid: a skin disease that causes large, tightly filled blisters to develop, usually affecting people over the age of 60.

- Pemphigus: a serious skin disease in which blisters develop if pressure is applied to the skin; the blisters burst easily, leaving raw areas that can become infected.

- Dermatitis herpetiformis: a skin disease that causes intensely itchy blisters, usually on the elbows, knees, back and buttocks. The blisters usually develop in patches of the same shape and size on both sides of the body.

- Chronic bullous dermatosis: a disease that causes clusters of blisters on the face, mouth or genitals.

- Cutaneous radiation syndrome

- Epidermolysis bullosa