No treatment of seborrheic keratoses is necessary, except for aesthetic reasons. Since a slightly increased risk of localized infection caused by picking at the lesion has been described, if a lesion becomes itchy or irritated by clothing or jewelry, a surgical excision is generally recommended.

Small lesions can be treated with light electrocautery. Larger lesions can be treated with electrodesiccation and curettage, shave excision, or cryosurgery. When correctly performed, removal of seborrheic keratoses will not cause much visible scarring except in persons with dark skin tones.

The virus is relatively hardy and immune to many common disinfectants. Exposure to 90% ethanol for at least 1 minute, 2% glutaraldehyde, 30% Savlon, and/or 1% sodium hypochlorite can disinfect the pathogen.

The virus is resistant to drying and heat, but killed by and ultraviolet radiation.

Gardasil 6 is an HPV vaccine aimed at preventing cervical cancers and genital warts. Gardasil is designed to prevent infection with HPV types 16, 18, 6, and 11. HPV types 16 and 18 currently cause about 70% of cervical cancer cases, and also cause some vulvar, vaginal, penile and anal cancers. HPV types 6 and 11 are responsible for 90% of documented cases of genital warts.

Gardasil 9, approved in 2014 protects against HPV types 6, 11, 16, 18, 31, 33, 45, 52, and 58.

HPV vaccines do not currently protect against the virus strains responsible for plantar warts (verrucas).

Seborrheic keratosis is the most common benign skin tumor. Incidence increases with age. There is less prevalence in people with darker skin. In large-cohort studies, 100% of the patients over age 50 had at least one seborrheic keratosis. Onset is usually in middle age, although they are common in younger patients too—found in 12% of 15-year-olds to 25-year-olds—making the term "senile keratosis" a misnomer.

Many different topical and systemic medications have been studied, including anti-inflammatories, antimycotics (target Candida species), carotenoids (precursors to vitamin A, e.g. beta carotene), retinoids (drugs similar to vitamin A), and cytotoxics, but none have evidence that they prevent malignant transformation in an area of leukoplakia.Vitamins C and E have also been studied with regards a therapy for leukoplakia. Some of this research is carried out based upon the hypothesis that antioxidant nutrients, vitamins and cell growth suppressor proteins (e.g. p53) are antagonistic to oncogenesis. High doses of retinoids may cause toxic effects. Other treatments that have been studied include photodynamic therapy.

A systematic review found that no treatments commonly used for leukoplakia have been shown to be effective in preventing malignant transformation. Some treatments may lead to healing of leukoplakia, but do not prevent relapse of the lesion or malignant change. Regardless of the treatment used, a diagnosis of leukoplakia almost always leads to a recommendation that possible causative factors such as smoking and alcohol consumption be stopped, and also involves long term review of the lesion, to detect any malignant change early and thereby improve the prognosis significantly.

Excision of the entire lesion, with adequate margin, will remove the lesion, allow full tissue diagnosis, and leave a planned surgical wound which can usually be repaired with a good cosmetic result. However, removing the entire lesion (especially on the face) may present difficult problems of plastic reconstruction. (On the nose and face, Mohs surgery may allow for good margin control with minimal tissue removal, but many insurance companies require the definitive diagnosis of a malignancy "before" they are prepared to pay the extra costs of Mohs surgery.) Especially in more cosmetically-sensitive areas, and where the clinical diagnosis is reasonably certain, alternatives to surgery may include no treatment (awaiting spontaneous resolution).

On the trunk, arms, and legs, electrodesiccation and curettage often suffice to control keratoacanthomas until they regress. Other modalities of treatment include cryosurgery and radiotherapy; intralesional injection of methotrexate or of 5-fluorouracil have also been used.

Recurrence after electrodesiccation and curettage can occur; it can usually be identified and treated promptly with either further curettage or surgical excision.

Common seborrheic keratosis (also known as "Basal cell papilloma," and "Solid seborrheic keratosis") is a common benign cutaneous condition characterized by a skin lesion with a dull or lackluster surface.

Keratoacanthoma usually occurs in older individuals. As with squamous cell cancer, it seems likely that ultraviolet light from the sun causes the development of KA. As with squamous cell cancer, sporadic cases have been found co-infected with the human papilloma virus (HPV).

Many new treatments for Melanoma are also known to increase the rate of Keratoacanthoma, such as the B-Raf inhibitor drugs Vemurafenib and Dabrafenib.

Myrmecia is one of the three types of warts that occurs on the skin on the hands and feet (palmoplantar). It is induced by human papilloma virus type 1 (HPV1). They occur on the palms of the hands, soles of the feet, and on the sides of the fingers and toes. The histology is abundant eosinophilic inclusion bodies associated with HPV1 E4 gene products. It was studied as far back as 42 B.C. - 37 A.D. by Aulus Cornelius Celsus.

A lentigo () (plural lentigines, ) is a small pigmented spot on the skin with a clearly defined edge, surrounded by normal-appearing skin. It is a harmless (benign) hyperplasia of melanocytes which is linear in its spread. This means the hyperplasia of melanocytes is restricted to the cell layer directly above the basement membrane of the epidermis where melanocytes normally reside. This is in contrast to the "nests" of multi-layer melanocytes found in moles (melanocytic nevi). Because of this characteristic feature, the adjective "lentiginous" is used to describe other skin lesions that similarly proliferate linearly within the basal cell layer.

Lentigines are distinguished from freckles (ephelis) based on the proliferation of melanocytes. Freckles have a relatively normal number of melanocytes but an increased "amount" of melanin. A lentigo has an increased "number" of melanocytes. Freckles will increase in number and darkness with sunlight exposure, whereas lentigines will stay stable in their color regardless of sunlight exposure.

Lentigines by themselves are benign, however one might desire the removal or treatment of some of them for cosmetic purposes. In this case they can be removed surgically, or lightened with the use of topical depigmentation agents. Some common depigmentation agents such as azelaic acid and kojic acid seem to be inefficient in this case, however other agents might work well (4% hydroquinone, 5% topical cysteamine, 10% topical ascorbic acid).

Conditions characterized by lentigines include:

- Lentigo simplex

- Solar lentigo (Liver spots)

- PUVA lentigines

- Ink spot lentigo

- LEOPARD syndrome

- Mucosal lentigines

- Multiple lentigines syndrome

- Moynahan syndrome

- Generalized lentiginosis

- Centrofacial lentiginosis

- Carney complex

- Inherited patterned lentiginosis in black persons

- Partial unilateral lentiginosis

- Peutz-Jeghers syndrome

- Lentigo maligna

- Lentigo maligna melanoma

- Acral lentiginous melanoma

A dermatologist or general physician usually administers combination therapy of drugs used for tuberculosis, such as Rifampicin, Isoniazid and Pyrazinamide (possibly with either streptomycin or ethambutol).

In longstanding scarred lesions, squamous cell carcinoma can develop.

Photodynamic therapy, cryotherapy (freezing), or local chemotherapy (with 5-fluorouracil) are favored by some clinicians over . Because the cells of Bowen's disease have not invaded the dermis, it has a much better prognosis than invasive squamous cell carcinoma.

Good results have been noted with the use of imiquimod for Bowen's disease, including on the penis (erythroplasia of Queyrat), although imiquimod is not (as of 2013) approved by the U.S. Food and Drug Administration for the treatment of any type of squamous cell carcinoma, and serious side effects can occur with use of imiquimod.

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.

Management for an individual with chronic mucocutaneous candidiasis consists of the following(relapse occurs once treatment is ceased, in many cases):

Rombo syndrome is a very rare genetic disorder characterized mainly by atrophoderma vermiculatum of the face, multiple milia, telangiectases, acral erythema, peripheral vasodilation with cyanosis and a propensity to develop basal cell carcinomas.

The lesions become visible in late childhood, began at ages 7 to 10 years and are most pronounced on the face, At that time a pronounced, somewhat cyanotic redness of the lips and hands was evident as well as moderate follicular atrophy of the skin on the cheeks. In adulthood, whitish-yellow, milia-like papules and telangiectatic vessels developed. The papules were present particularly on the cheeks and forehead, gradually becoming very conspicuous and dominating the clinical picture. Trichoepitheliomas were found in 1 case. In adults, the eyelashes and eyebrows were either missing or irregularly distributed with defective and maldirected growth. Basal cell carcinomas were a frequent complication. The skin atrophy was referred to as vermiculate atrophoderma. Basal cell carcinomas may develop around the age of 35. Histological observations during the early stage include irregularly distributed and atrophic hair follicles, milia, dilated dermal vessels, lack of elastin or elastin in clumps. After light irradiation a tendency to increased repair activity was observed both in epidermis and in the dermal fibroblasts.

Histologic sections showed the dermis to be almost devoid of elastin in most areas with clumping of elastic material in other areas. The disorder had been transmitted through at least 4 generations with instances of male-to-male transmission.

Squamous cell carcinoma of eye tissues is one of the most frequent neoplasms of cattle.

Clear cell acanthoma (also known as "Acanthome cellules claires of Degos and Civatte," "Degos acanthoma," and "Pale cell acanthoma") is a benign clinical and histological lesion initially described as neoplastic, which some authors now regard as a reactive dermatosis. It usually presents as a moist solitary firm, brown-red, well-circumscribed, 5 mm to 2 cm nodule or plaque on the lower extremities of middle-aged to elderly individuals The lesion has a crusted, scaly peripheral collarette and vascular puncta on the surface. It is characterized by slow growth, and may persist for years. The clinical differential diagnosis includes: dermatofibroma, inflamed seborrheic keratosis, pyogenic granuloma, basal cell carcinoma, squamous cell carcinoma, verruca vulgaris, psoriatic plaque, and melanoma.

While most cases require no treatment, therapy options include cryotherapy, application of a topical salicylic acid compound, surgical and laser ablation.

Most conjunctival squamous cell carcinomas are removed with surgery. A few selected cases are treated with topical medication. Surgical excision with a free margin of healthy tissue is a frequent treatment modality. Radiotherapy, given as external beam radiotherapy or as brachytherapy (internal radiotherapy), can also be used to treat squamous cell carcinomas.

Nevus sebaceus or sebaceous nevus (the first term is its Latin name, the second term is its name in English; also known as an "organoid nevus" and "nevus sebaceus of Jadassohn") is a congenital, hairless plaque that typically occurs on the face or scalp. Such nevi are present at birth, or early childhood, affecting males and females of all races equally. The condition is named for an overgrowth of sebaceous glands in the area of the nevus.

Skin growths such as benign tumors and basal cell carcinoma can arise in sebaceous nevi, usually in adulthood. Rarely, sebaceous nevi can give rise to sebaceous carcinoma. However, the rate of such malignancies is now known to be less than had been estimated. For this reason, excision is no longer automatically recommended.

Appropriate sun-protective clothing, use of broad-spectrum (UVA/UVB) sunscreen with at least SPF 50, and avoidance of intense sun exposure may prevent skin cancer.

Heck's disease (also known as focal or multifocal epithelial hyperplasia) is an asymptomatic, benign neoplastic condition characterized by multiple white to pinkish papules that occur diffusely in the oral cavity. Can present with slightly pale, smooth or roughened surface morphology. It is caused by the human papilloma virus types 13 and 32. It exhibits surface cells with vacuolated cytoplasm around irregular, pyknotic nuclei and occasional cells with mitosis-like changes within otherwise mature and well-differentiated epithelium. A distinguishing histologic feature is elongated rete ridges resembling Bronze Age axe with mitosoid bodies present. It was first identified in the Aboriginal population.

Over time, they will spontaneously regress without treatment. Possible treatment may be excisional biopsy for lesions of functional or aesthetic concern.

Clear cell acanthoma is characterized by a sharply demarcated psoriasiform epidermal hyperplasia composed of a proliferation of slightly enlarged keratinocytes, and basal cells with pale-staining glycogen-rich cytoplasm, mild spongiosis and scattered neutrophils, which may form small intraepidermal microabscesses. Oedematous dermal papillae are typically seen with increased vascularity and a mixed inflammatory infiltrate including lymphocytes, plasma cells and neutrophils.