Numerous treatment options are available for photoaged skin, including dermabrasion, topical application of retinoic acid, carbon dioxide laser resurfacing, hyaluronic acid injection into the dermis, imiquimod, tacrolimus ointment, and topical oestrogen therapy. These treatments have variable efficacy.

The most effective prevention strategy for photoaging remains minimization of sun exposure, through use of sunscreen and other sun exposure avoidance measures.

Ultraviolet radiation is believed to contribute to the development of actinic keratoses by inducing mutations in epidermal keratinocytes, leading to proliferation of atypical cells. Therefore, preventive measures for AKs are targeted at limiting exposure to solar radiation, including:

- Limiting extent of sun exposure

- Avoid sun exposure during noontime hours when UV light is most powerful

- Using sun protection

- Frequently applying powerful sunscreens with SPF ratings greater than 30 and that also block both UVA and UVB light

- Wearing sun protective clothing such as hats, long-sleeved shirts, long skirts, or trousers

Recent research implicating human papillomavirus (HPV) in the development of AKs suggests that HPV prevention might in turn help prevent development of AKs, as UV-induced mutations and oncogenic transformation are likely facilitated in cases of active HPV infection.

To prevent AC from developing, protective measures could be undertaken such as avoiding mid-day sun, or use of a broad-brimmed hat, lip balm with anti UVA and UVB ingredients (e.g. para-aminobenzoic acid), or sun blocking agents (e.g. zinc oxide, titanium oxide) prior to sun exposure.

There are many treatment options for AK depending on the patient and the clinical characteristics of the lesion. AKs show a wide range of features, which guide treatment decision-making. Although overall cure rates are high, experts agree that the best treatment for AK is prevention. Regular follow-up is advisable after any treatment to make sure no new lesions have developed and that old ones are not progressing.

This condition is considered premalignant because it may lead to squamous cell carcinoma in about 10% of all cases. It is not possible to predict which cases will progress into SCC, so the current consensus is that all lesions should be treated.

Treatment options include 5-fluorouracil, imiquimod, scalpel vermillionectomy, chemical peel, electrosurgery, and carbon dioxide laser vaporization. These curative treatments attempt to destroy or remove the damaged epithelium. All methods are associated with some degree of pain, edema, and a relatively low rate of recurrence.

Actinic elastosis, also known as solar elastosis, is an accumulation of abnormal elastin (elastic tissue) in the dermis of the skin, or in the conjunctiva of the eye, which occurs as a result of the cumulative effects of prolonged and excessive sun exposure, a process known as photoaging.

Currently there is no cure for actinic prurigo, and treatment focuses on relieving the dermatologic symptoms, by way of topical steroid creams or systemic immunosuppressants.

Prescribed treatments include:

- topical creams such as Tacrolimus and Betamethasone.

- systemic immunosuppressants such as Prednisone.

- In some cases, Thalidomide has proven to be effective in controlling the symptoms of actinic prurigo.

All patients with AP are encouraged to minimize sun exposure, and to use strong sunscreen throughout the year, and even on cloudy or overcast days, as UVA light, unlike UVB light, is able to penetrate cloud cover and remains constant throughout the day.

Alternative treatment methods might include UV Hardening, Meditation and/or cognitive behavioral therapy. UV-A desensitization phototherapy has also been shown to be effective in cases.

UV irradiation can be utilized after curetting the hyperkeratosis with a combination medication treatment of oral retinoids, psoralen and Ultraviolet A radiation.

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.

Isotretinoin, high doses of vitamin A and tretinoin cream can be utilized. Also, emollients, oral antihistamines, and antipruritic creams that contain menthol and camphor may be helpful because the lesions can become very itchy.

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.

Actinic granuloma (also known as "O'Brien granuloma") is a cutaneous condition characterized histologically by a dermal infiltrate of macrophages.

Actinic granuloma is an asymptomatic granulomatous reaction that affects sun-exposed skin, most commonly on the face, neck, and scalp.

It is characterized by annular or polycyclic lesions that slowly expand centrifugally and have an erythematous elevated edge and a hypopigmented, atrophic center.

Advise to reduce exposure to the sun and to use sunscreen.

Treatment with topical halometasone cream, pimecrolimus cream.

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.

Solar purpura (also known as "Actinic purpura," and "Senile purpura") is a skin condition characterized by large, sharply outlined, 1- to 5-cm, dark purplish-red ecchymoses appearing on the dorsa of the forearms and less often the hands.

The condition is most common in elderly people of European descent. It is caused by sun-induced damage to the connective tissue of the skin.

No treatment is necessary. The lesions typically fade over a period of up to 3 weeks.

Porokeratosis is a specific disorder of keratinization that is characterized histologically by the presence of a cornoid lamella, a thin column of closely stacked, parakeratotic cells extending through the stratum corneum with a thin or absent granular layer.

Chronic exposure to ultraviolet light can result in skin thickening as well as elastic destruction of the skin. At least in one instance, the occupational exposure to the UVA light of the sun (UVB is blocked by many car windows) resulted in skin destruction on one side of the face.

Disseminated superficial actinic porokeratosis (DSAP) is a non-contagious skin condition with apparent genetic origin in the SART3 gene. It most often presents in sun-exposed areas of the body. Some DSAP cases have been reported in patients with acute immune compromised situations, particularly in the elderly. For those with sun damaged skin, the lesions usually begin to appear in the patient's 20s and increase in number and visibility in the 40s or 50s. Commonly, though not always, the number and visibility of lesions is in direct proportion to the amount of sun damage to the affected area.

Lesions generally are characterized by an irregularly shaped thread-like ring that is usually the size of a pencil eraser, though lesions vary and may be half or double that size. The thread-like ring is very thin, much like fabric thread for sewing, and raised such that it is both palpable and visible. The interior of the ring may be rough like sandpaper, or smooth. The interior is often discolored, though colors vary from patient to patient. Lesions, due to their vascular nature, can also vary according to body temperature, environmental temperatures, and other external stimuli. The internal ring color is most often reddish, purplish, pink, or brown.

Some patients report itching and irritation associated with the condition, and many report no notable sensation. Although no known hormonal link has been found, DSAP occurs more commonly in women.

A study in 2000 was done on a Chinese family, in which a locus for a gene was located.

The cause for actinic prurigo is unknown, however researchers believe that protein in our bodies may be a cause to the condition also:

•UV-A and UV-B light seem to be the main provoking agents. This observation is supported by the fact that most patients live at high altitudes (>1000 m above sea level), and the condition improves in many patients when they move to lower altitudes. However, some patients who are affected already live at sea level.18,19,27 •Some authors are considering a food photosensitizer or a nutritional selective deficiency as a cause; however, no evidence proves this theory.27

Favre–Racouchot syndrome (also known as "Favre–Racouchot disease", and "nodular cutaneous elastosis with cysts and comedones") is a disorder consisting of multiple open comedones that occurs in skin damaged by sunlight, especially under and lateral of the eyes. The comedones are widened openings for hair follicles and sebaceous glands filled with material.

Keratosis (from "keratinocyte", the prominent cell type in the epidermis, and , abnormal) is a growth of keratin on the skin or on mucous membranes. More specifically, it can refer to:

- actinic keratosis (also known as solar keratosis)

- hydrocarbon keratosis

- keratosis pilaris (KP, also known as follicular keratosis)

- seborrheic keratosis

Actinic keratoses are pre-malignant growths. Seborrheic keratoses are not pre-malignant.

Porokeratosis may be divided into the following clinical types:

- "Plaque-type porokeratosis" (also known as "Classic porokeratosis" and "Porokeratosis of Mibelli") is characterized by skin lesions that start as small, brownish papules that slowly enlarge to form irregular, annular, hyperkeratotic or verrucous plaques. Sometimes they may show gross overgrowth and even horn-like structures may develop. Skin malignancy, although rare, is reported from all types of porokeratosis. Squamous cell carcinomata have been reported to develop in Mibelli's type porokeratosis over partianal areas involving anal mucosa. This was the first report mentioning mucosal malignancy in any form of porokeratosis.

- "Disseminated superficial porokeratosis" is a more generalized processes and involves mainly the extremities in a bilateral, symmetric fashion. In about 50% of cases, skin lesions only develop in sun-exposed areas, and this is referred to as "disseminated superficial actinic porokeratosis"

- "Porokeratosis palmaris et plantaris disseminata" is characterized by skin lesions that are superficial, small, relatively uniform, and demarcated by a distinct peripheral ridge of no more than 1mm in height.

- "Linear porokeratosis" is characterized clinically skin lesions are identical to those of classic porokeratosis, including lichenoid papules, annular lesions, hyperkeratotic plaques with central atrophy, and the characteristic peripheral ridge.

- "Punctate porokeratosis" is a skin condition associated with either classic porokeratosis or linear porokeratosis types of porokeratosis, and is characterized by multiple, minute, and discrete punctate, hyperkeratotic, seed-like skin lesions surrounded by a thin, raised margin on the palms and soles.

- "Porokeratosis plantaris discreta" is a skin condition that occurs in adults, with a 4:1 female preponderance, characterized by a sharply marginated, rubbery, wide-based papules. It is also known as "Steinberg's lesion". It was characterized in 1970.

Calluses and corns may go away by themselves eventually, once the irritation is consistently avoided. They may also be dissolved with keratolytic agents containing salicylic acid, sanded down with a pumice stone or silicon carbide sandpaper or filed down with a callus shaver, or pared down by a professional such as a podiatrist or a foot health practitioner.

Corns and calluses are easier to prevent than to treat. When it is usually not desirable to form a callus, minimizing rubbing and pressure will prevent callus formation. Footwear should be properly fitted, gloves may be worn, and protective pads, rings or skin dressings may be used. People with poor circulation or sensation should check their skin often for signs of rubbing and irritation so they can minimize any damage.

Elastosis perforans serpiginosa is a unique perforating disorder characterized by transepidermal elimination of elastic fibers and distinctive clinical lesions, which are serpiginous in distribution and can be associated with specific diseases.

Perforating calcific elastosis (also known as "Localized acquired cutaneous pseudoxanthoma elasticum," "Perforating periumbilical calcific elastosis," and "Periumbilical perforating pseudoxanthoma elasticum") is an acquired, localized cutaneous disorder, most frequently found in obese, multiparous, middle-aged women, characterized by lax, well-circumscribed, reticulated or cobble-stoned plaques occurring in the periumbilical region with keratotic surface papules.