Grover's disease often starts quite suddenly. There are intensely itchy spots on the central back, mid chest and occasionally elsewhere. Frequently, it follows sweating or some unexpected heat stress.

The itchy eruption lasts an average of 10–12 months. It is characterized by papules and papulovesicles with excoriations occurring on the chest, back, lower sternum, arms, and thighs. The papules are most commonly found on the mid chest.

Sometimes the features of Grover's are found in people who do not itch or have a conspicuous rash. Most of the people with Grover's who visit a dermatologist, however, itch a lot.

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.

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.

Pigmented purpuric dermatosis (also known as "progressive pigmentary dermatosis," "purpura pigmentosa chronica," "pigmentary purpuric eruptions," or "progressive pigmenting purpura" or "Schamberg's disease") refers to one of the three major classes of skin conditions characterized by purpuric skin eruptions.

Pigmented purpuric dermatosis are distinguished from other purpura by size (0.3–1 cm) and are most often seen in the lower extremities. Pigmentary purpuric eruptions may present with one of several clinical patterns. There may be overlapping characteristics among pigmented purpuric dermatosis and between their signs and those of other purpuric eruptions. Examples of the pigmented purpuric dermatosis group include:

Although vascular damage may be present, it is insufficient for these conditions to be considered forms of vasculitis.

The lesions are most frequent on the lower limbs, but may occur anywhere on the body, including the hands, arms, torso and even the neck. They may vary in number and erupt in mass numbers.

They consist of irregular patches of orange or brown pigmentation with characteristic "cayenne pepper" spots appearing within and at the edge of old lesions.

There are usually no symptoms, although there may be some slight itching, but there is no pain.

The eruption may persist for many years. The pattern of the eruption changes, with slow extension and often some clearing of the original lesions.

Schamberg's disease, or progressive pigmented purpuric dermatitis, is a chronic discoloration of the skin which usually affects the legs and often spreads slowly. This disease is more common in males and may occur at any age from childhood onward. This condition is observed worldwide and has nothing to do with race or ethnic background.

Although other forms of the disease occur at younger ages, some individuals start having long term symptoms at thirty years of age. This disease also affects adolescents and young adults. This also affects the immune system which therefore results in rashes. The symptoms rarely affect the face or scalp, but occurs at other sites of the body. The duration may last for months or even several years. For instance, new crops of lesions appear every few weeks.

Although lichen planus can present with a variety of lesions, the most common presentation is as a well defined area of purple-coloured, itchy, flat-topped papules with interspersed lacy white lines (Wickham's striae). This description is known as the characteristic "6 Ps" of lichen planus: planar (flat-topped), purple, polygonal, pruritic, papules, and plaques. This rash, after regressing, is likely to leave an area of hyperpigmentation that slowly fades. That said, a variety of other lesions can also occur.

Lichen striatus is defined by:

The papules could be smooth, flat topped or scaly. The band of lichen striatus varies from a few millimeters to 1-- 2 cm wide and extends from a few centimeters to the complete length of the extremity. By and big, the papules are unilateral and single on an extremity along the lines of Blaschko.

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.

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

Grover's disease (GD) is a polymorphic, pruritic, papulovesicular dermatosis characterized histologically by acantholysis with or without dyskeratosis. Once confirmed, most cases of Grover's disease last six to twelve months, which is why it was originally called "transient". However it may last much longer. Nevertheless, it is not to be confused with relapsing linear acantholytic dermatosis.

Variants of cutaneous lichen planus are distinguished based upon the appearance of the lesions and/or their distribution. Lesions can affect the:

- Extremities (face, dorsal hands, arms, and nape of neck). This is more common in Middle Eastern countries in spring and summer, where sunlight appears to have a precipitating effect.

- Palms and soles

- Intertriginous areas of the skin. This is also known as "Inverse lichen planus."

- Nails characterized by irregular longitudinal grooving and ridging of the nail plate, thinning of the nail plate, pterygium formation, shedding of the nail plate with atrophy of the nail bed, subungual keratosis, longitudinal erthronychia (red streaks), and subungual hyperpigmentation. A sand-papered appearance is present in around 10% of individuals with nail lichen planus.

- Hair and Scalp. The scalp is rarely affected by a condition known as lichen planopilaris, acuminatus, follicular lichen planus, and peripilaris, characterised by violaceous, adherent follicular scale with progressive scarring alopecia. While lichen planus and lichen planopilaris may occur together, aside from sharing the term ‘lichen’ and revealing inflammation on skin biopsy, there is neither established data on their co-occurrence nor data to suggest a common etiology. Lichen planopilaris is considered an orphan disease with no definitive prevalence data and no proven effective treatments.

Other variants may include:

- "Lichen planus pemphigoides" characterized by the development of tense blisters atop lesions of lichen planus or the development vesicles de novo on uninvolved skin.

- "Keratosis lichenoides chronica" (also known as "Nekam's disease") is a rare dermatosis characterized by violaceous papular and nodular lesions, often arranged in a linear or reticulate pattern on the dorsal hands and feet, extremities, and buttock, and some cases manifest by sorrheic dermatitis-like eruption on the scalp and face; also palmo plantar keratosis has been reported.

- "Lichenoid keratoses" (also known as "Benign lichenoid keratosis," and "Solitary lichen planus") is a cutaneous condition characterized by brown to red scaling maculopapules, found on sun-exposed skin of extremities. Restated, this is a cutaneous condition usually characterized by a solitary dusky-red to violaceous papular skin lesion.

- "Lichenoid dermatitis" represents a wide range of cutaneous disorders characterized by lichen planus-like skin lesions.

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.

Symptoms include:

1. yellow-brown, banana-shaped fibers

2. caviar-like papules

3. brown-grey or blue-black hyper-pigmentation

The majority of the lesions will be seen on areas of the body that get the most sun.

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.

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.

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.

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

There are two expressions of this condition, one for long or double coated breeds and one for short coated breeds, both with differing presentations.

- For long- or double-coated breeds such as Poodles, Akitas and Samoyeds, the condition often presents itself with silvery dandruff which adheres to the coat, hair loss (not to be confused with moulting or "blowing coat"), a dull and brittle coat, and later on skin lesions along the back and ears as well as thickened skin and a musty or rancid odour.

- For short-coated breeds such as Vizslas, the condition causes facial swellings, nodular skin lesions, fine dandruff which does not adhere to the coat, and a general "moth-eaten" appearance to the coat.

There are several types of pemphigus which vary in severity: pemphigus vulgaris, pemphigus foliaceus, Intraepidermal neutrophilic IgA dermatosis, and paraneoplastic pemphigus.

- Pemphigus vulgaris (PV - ICD-10 L10.0) is the most common form of the disorder and occurs when antibodies attack "Desmoglein 3". Sores often originate in the mouth, making eating difficult and uncomfortable. Although pemphigus vulgaris may occur at any age, it is most common among people between the ages of 40 and 60. It is more frequent among Ashkenazi Jews. Rarely, it is associated with myasthenia gravis. Nail disease may be the only finding and has prognostic value in management.

- Pemphigus foliaceus (PF) is the least severe of the three varieties. "Desmoglein 1", the protein that is destroyed by the autoantibody, is found in only the top dry layer of the skin. PF is characterized by crusty sores that often begin on the scalp, and may move to the chest, back, and face. Mouth sores do not occur. This form is also frequent among Ashkenazi Jews. It is not as painful as pemphigus vulgaris, and is often mis-diagnosed as dermatitis or eczema

- Intraepidermal neutrophilic IgA dermatosis is characterized histologically by intraepidermal bullae with neutrophils, some eosinophils, and acantholysis.

- The least common and most severe type of pemphigus is paraneoplastic pemphigus (PNP). This disorder is a complication of cancer, usually lymphoma and Castleman's disease. It may precede the diagnosis of the tumor. Painful sores appear on the mouth, lips, and the esophagus. In this variety of pemphigus, the disease process often involves the lungs, causing bronchiolitis obliterans (constrictive bronchiolitis). Though much less frequent, it is still found the most in the Ashkenazi Jewish population. Complete removal of and/or cure of the tumor may improve the skin disease, but lung damage is generally irreversible.

- Endemic pemphigus foliaceus, including the Fogo Selvagem, the new variant of endemic pemphigus folaiceus in El Bagre, Colombia, South America, and the Tunisian endemic pemphigus in North Africa.

Note that Hailey-Hailey disease, also called familial benign pemphigus, is an inherited (genetic) skin disease, not an autoimmune disease. It is therefore not considered part of the Pemphigus group of diseases.

Sebaceous adenitis in an uncommon skin disease found in some breeds of dog, and more rarely in cats, rabbits and horses. characterised by an inflammatory response against the dog's sebaceous glands (glands found in the hair follicles in the skin dermis), which can lead to the destruction of the gland. It was first described in veterinary literature in the 1980s.

Prurigo gestationis (also called "Besnier prurigo", "Early-onset prurigo of pregnancy," "Linear IgM dermatosis of pregnancy," "Papular dermatitis of pregnancy," "Prurigo of pregnancy", and "Spangler's papular dermatitis of pregnancy") is an eruption consisting of pruritic, excoriated papules of the proximal limbs and upper trunk, most often occurring between the 20th and 34th week of gestation.

The exact etiology is unknown, but it is considered likely to be a flareup of atopic dermatitis during pregnancy.

It is sometimes considered to be a term encompassing Besnier prurigo and other conditions.

It is sometimes considered a diagnosis of exclusion.

Pustulosis palmaris et plantaris (also known as pustulosis of palms and soles, palmoplantar pustulosis, persistent palmoplantar pustulosis, pustular psoriasis of the Barber type, and pustular psoriasis of the extremities) is a chronic recurrent pustular dermatosis (that is, a pustulosis or pustular psoriasis) localized on the palms and soles only, characterized histologically by intraepidermal pustules filled with neutrophils. It can occur as part of the SAPHO syndrome.

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.

Kyrle disease symptoms are chronic and have an onset during adulthood between the ages of 30 and 50 years of age. However, there were reported cases of early onset as early as 5 years of age and late onset as late as 75 years of age. The main symptom is the development of small papules into painless lesions that are surrounded by silvery scales. The lesions are painless, however, there is a chance that the patient may experience extreme urges to itch them. In time, these lesions grow up to a radius of 0.75 inch and develop into red-brown nodules with a central plug of keratin. As more lesions develop, they can come together and form larger keratotic plaques. These lesions are usually observed on the lower extremities, however, can also develop on the upper extremities, such as, the arms, the head and the neck. The only parts of the body that Kyrle disease do not form are the palms, soles, and mucous membranes. Lesions may heal spontaneously without treatment, however, new ones will develop in its place.

Other symptoms that may be observed:

- Hyperkeratotic cone-shaped papular plugs

- Hyperkeratotic verrucous plaques

- Diabetes mellitus

- Hepatic insufficiency

- Presence of albumin in the urine

- Excess sugar in the urine