Skin Care

What is acne?

Keratolytic acne treatments

• azelaic acid, a natural product of a yeast that lives on normal skin, with antibacterial and anti-inflammatory activity.


• tretinoin and iso tretinoin are active metabolite of Vitamin A known as retinoids that stimulates skin cell proliferation, promoting growth of new skin cells to speed up skin cell turnover. They are available as creams and gels; tretinoin is also available is a gel containing microspheres that increases drug delivery direct into the hair follicles. These retinoids also block the activity of inflammatory cells like leukocytes and the production of inflammatory chemicals, which inhibits the inflammatory reaction. Tazarotene is also a retinoid and is a pro-drug of Vitamin A.


• adapalene, is a retinoid-like compound with similar activity to tretinoin suitable for topical treatment of mild acne, but is more stable and more fat soluble and becomes trapped in the hair follicles.


• benzoyl peroxide, an antiseptic and oxidising agent, with anti-inflammatory properties.

Antibacterial treatments

• Topical antibiotics like clindamycin and erythromycin are used for mild to moderate acne. They are applied as a cream or gel that absorbs rapidly into the skin and penetrates the comedomes where they act directly on the Propionibacterium acnes bacteria, inhibiting bacterial protein synthesis, which kills the bacteria. They also reduce the amount of fatty acids in the skin that the bacteria live on.


• Oral antibiotics are used to treat more severe cases of infected acne, including cystic and pustular types of acne lesions. Doxycycline and minocycline both broad-spectrum antibiotics belonging to the tetracycline group of antibiotics and inhibit protein synthesis in susceptible bacteria, including Propionibacterium acnes.


• Other topical acne medications also have antibacterial activity. These include azelaic acid and benzoyl peroxide that penetrate the skin and reduce growth of the Propionibacterium acnes bacteria, which helps prevent the spread of infection. They also inhibit the production of acne-promoting fatty acid, which helps unblock the pores and promotes healing.

Anti-inflammatory treatments for acne

Anti-androgen hormonal therapy

Rosacea

Types of skin infection

Topical treatments for skin infections

Topical antibiotics prevent spread of bacteria and allow the infected skin to heal. 

They include:

• Sodium fusidate, a topical antibiotic that blocks bacterial protein synthesis, and inhibits bacterial replication, but does not kill the bacteria.  It is very soluble in fat and water and penetrates the skin easily to get to the site of infection, which makes it a very efficient topical antibiotic.  
• Mupirocin, a topical antibiotic that inhibits protein and RNA synthesis, which blocks growth and replication of these bacteria and kills the bacteria.
• Neomycin a broad spectrum topical antibiotic that blocks bacterial protein synthesis needed for replication, and although it does not absorb into the skin, it is effective in preventing the spread of bacteria in the skin.  The antibiotic ointment is also combined with an anti-inflammatory corticosteroid to reduce inflammation in infected inflammatory skin disorders.

Types of fungal infection

• Tinea, a dermatophyte fungus that lives on human skin and promotes a reaction as it grows through the skin by small filaments called hyphae, causing symptoms including, inflammation, itching and rash, which can become severe. Tinea can infect many parts of the body causing infections like athlete's foot (tinea pedis), ringworm or tinea of the body (tinea corporis), tinea of the groin or jock itch (tinea cruris) and tinea of the scalp (tinea capitis).


• Candida, a yeast that normally inhabits the gastrointestinal tract but when immunity is low or following a course of antibiotics, it can become overgrown and cause an infection called candidiasis or thrush. Areas infected by Candida include mucous membranes usually in the mouth, throat and genitals; Candida can also infect the skin and if the infection becomes systemic this can be more serious.


• Infections of the finger nails and toe nails (onychomycosis) can be caused by Tinea or Candida, also by moulds, which are a different type of fungus.


• Malassezia, a yeast normally found in the skin that can overgrow and cause problems like dandruff, when the rate at which dead skin cells are shed and replaced begins to speed up, as a reaction to irritation by the fungus.


• Histoplasma that causes histoplasmosis, a rare systemic fungal infection from inhalation of a soil fungus into the lung causing flu-like symptoms and is an opportunistic infection common to people who are immunocompromised, such as due to HIV infection.

Types of anti-fungal medication

• Terbinafine, a broad spectrum antifungal drug that is used to treat a variety of fungal infections, and is particularly effective against tinea and candida. It is available as a cream for topical treatment and as tablets for oral administration.


• Miconazole oral gel an antifungal drug, belonging to the imidazole group of antifungals that is used as a topical treatment for oral thrush.


• Fluconazole a broad-spectrum antifungal drug belonging to the triazole group that is used to treat thrush and tinea and is available for oral administration as capsules and tablets.


• Ketoconazole, a synthetic broad-spectrum antifungal drug that is used to treat a variety of fungal infections in several parts of the body, including pityriasis of the skin, candidiasis or thrush of the mouth and vagina and also systemic fungal infections. It is available as a cream or shampoo for topical treatment and as tablets for oral administration.

Antifungal application

What is scabies?

Treatment for scabies infection

What are cold sores?

Treatments for cold sores

What are haemorrhoids?

Treatment for haemorrhoids

What is psoriasis?

Treatment for psoriasis

Conditions of the scalp

Many skin conditions that affect the rest of the body also affect the scalp and cause itching, redness, scaling and crusting of the skin of the scalp.  These include

• inflammatory skin conditions, like dermatitis and eczema
• seborrhoeic dermatitis
• dandruff
• psoriasis

Dermatitis is a general term that applies to inflammation of the skin and can occur affect any area of the skin, including the scalp.  There are many possible causes for dermatitis such as an allergic reaction, contact with an irritant or excessively dry skin.  Eczema, another term for dermatitis usually refers to chronic itchy inflammatory skin condition that is also known as atopic eczema or atopic dermatitis, as there is a genetic predisposition due to an inherited atopic tendency, with a family history of three closely linked conditions: asthma, eczema and hay fever.

Seborrhoeic dermatitis is a chronic form of dermatitis that affects the scalp and is thought to be due to an inflammatory reaction to a common inhabitant of the skin, the yeast fungus Malassezia (previously called Pityrosporum) that lives in the sebum.  Symptoms include greasy scaling of the scalp with itchy red and crusty patches and flaky persistent dandruff, which is a common mild form of seborrhoeic dermatitis, characterised by flaking of the skin on the scalp.  

Treatments for scalp conditions

Medications used to treat inflammatory skin conditions of the scalp contain a range of ingredients that work by different mechanisms of action.

• Clobetasol and fluocinolone are potent synthetic corticosteroid hormones with anti-inflammatory action based on blocking the production of chemicals that are inflammatory mediators, particularly prostaglandins and leukotrienes.  This action prevents migration of inflammatory cells, which helps dampen down the inflammatory response; reducing capillary wall permeability and promoting vasoconstriction, which causes blood vessel narrowing, and helps reduce swelling and redness. 
• Ketonazole is an antifungal that kills the yeast fungus Malassezia responsible for seborrhoeic dermatitis, by inhibiting the synthesis of ergosterol, an important component of fungal cell membrane that weakens the membrane and kills the fungus.  Zinc pyrithione is a chemical antifungal that is sometimes used in combination with ketonazole to enhance its antifungal action.
• Salicylic acid is a keratolytic that is included in treatments for hyperkeratotic conditions, which are scaly skin conditions where the skin has become thickened, scaly and flaky.  It works by softening keratin, which is a fibrous structural protein found in the upper layer of the skin, and this helps loosen the dry scaly skin and also allows other medications like corticosteroids to penetrate the skin more easily.  
• Coal tar is also used for hyperkeratotic conditions to reduce scaling itching and inflammation, due to its antimicrobial and antipruritic (reduces itching) properties.  It is also a keratoplastic and interacts with skin cells to slow down the rapid growth of keratinocytes to normal turnover so that dead cells are shed from the surface, which reduces scaling. 
• Calcipotroil is used as a topical treatment for psoriasis and helps to prevent over production of hardened keratinocytes, restores normal cell growth and behaviour to the epidermal skin cells, as well as reducing inflammation.  Calcipotroil, a derivative of calcitriol or Vitamin D works by regulating cell growth and differentiation and modulating the immune system, causing inhibition of cell proliferation and stimulation of cell differentiation.  This action helps reduce the scaling and thickening of psoriatic plaques and relieves symptoms of psoriasis. 

Aging, free radicals and damaged skin

The environment, particularly exposure to UV from the sun, contributes to skin damage and together with the natural aging process causes the appearance of fine lines and wrinkles. 

Free radicals are unstable and highly reactive chemicals produced by oxidation, which is a chemical reaction that occurs in the body as a result of normal metabolism or due to environmental factors such as UV radiation or pollution and cigarette smoke.  Free radicals can cause cell damage and cell death and are thought to contribute to skin damage.  Antioxidants are stable compounds that neutralise free radicals and therefore, protect against the damage they can cause.  Some antioxidants like glutathione occur naturally in the body, they can also be obtained from the diet in a range of fruits and vegetables, such as Vitamin E, the most common fat-soluble antioxidant and Vitamin C, the most common water-soluble antioxidant. 

Dietary supplements 

The visible signs of aging and the impact of the environment on the skin include dryness, fine lines and wrinkles and dullness of complexion.  These signs are a reflection of changes in the epidermis and dermis layers of the skin due to environmental damage, loss of collagen and elastin, and loss of moisture, resulting in reduced elasticity and thinning of the skin. 

Topical treatments

Certain medications that are generally used for treating acne can also be helpful for reducing skin blemishes, including azaleic acid and tretinoin. 

Tretinoin is an active metabolite of Vitamin A that interacts with retinoid receptors in skin cells and affects several processes, including cell growth, proliferation and differentiation, and production of sebum.  It also increases collagen and elastin production and inhibits the activity of certain enzymes that break down collagen and elastin.  Tretinoin works by blocking the keratinisation process, which is hardening of the outer skin layer due to deposition of keratin; also by promoting skin turnover replacing old damaged skin with new skin, which helps the natural exfoliation process of the outer skin layer.  Increased collagen helps restore skin flexibility.  All these actions contribute to the anti-aging action of tretinoin, which can be used as topical treatment in a cream or gel to reduce visible signs of ageing on the face, including age spots and fine wrinkles.  Other effects include lightening of age spots or pigmented patches of skin. 

Treatments for scars

References 

Vitiligo

Skin discolouration

Lightening the skin

What is an inflammatory skin condition?

Examples of inflammatory skin conditions

• Eczema, a chronic itchy skin condition caused by inflammation of the epidermis or outer layer of skin. It is also known as atopic eczema or atopic dermatitis, as there is a predisposition due to an inherited atopic tendency, with a family history of three closely linked conditions: asthma, eczema and hay fever.


• Irritant contact dermatitis, which is caused by direct skin contact with an irritant like solvents and harsh chemicals.


• Allergic contact dermatitis, an allergic reaction caused by contact with a substance that triggers a delayed immune hypersensitivity reaction in response to a specific allergy such as to perfume, latex or nickel.


• Seborrhoeic dermatitis, also known as cradle cap in babies, is a scaly rash that usually affects areas of the face or scalp that are greasy or oily, causing peeling similar to dandruff.


• Neurodermatitis, a repeated rubbing or scratching due to a constant itch scratch cycle, causing a thickened pigmented patch of skin.


• Lichen planus, an abnormal immune reaction, in which the body’s immune cells attack self but may also be a reaction to a medication or to a viral infection. Symptoms include, papules (bumps on the skin) forming a rash with raised reddened patches and they can occur anywhere on the skin, particularly the wrist, ankles and lower back; also on mucous membranes like the mouth.


• Psoriasis a non-allergic, chronic automimmune skin condition that has a genetic predisposition, where certain cells of the immune system overproduce inflammatory chemicals that stimulate excessive growth and proliferation of keratinocytes (epidermal skin cells), causing thickening and scaling of the skin as well as inflammation. Symptoms including red scaly patches of skin ranging from mild to severe with psoriatic lesions covering large areas of the body and causing extreme itching, pain and discomfort.


• Discoid lupus erythematosus is a chronic autoimmune condition that affects the skin usually of the face, ears and scalp but can affect other parts. Symptoms include red scaly patches with sores and inflammation leaving and scarring.


• Mouth ulcers originally caused by injury to or infection of the skin, which develops into an inflammatory lesion.

How corticosteroids work

Application of topical corticosteroids

• A protective, emollient (soothing and moisturising) dental paste containing triamcinalone for mouth ulcers.


• Creams containing triamcinalone, mometasone, hydrocortisone, betamethasone and clobetasol are best used for moist lesions skin that is inflamed and itchy, as they can be rubbed into the skin without being greasy and have emollient (soothing and moisturising) properties.


• Ointments containing mometasone and clobetasol can be used for dry scaling and fissured (cracked due to dryness) lesions as they contain a mixture of oil and water that helps keep moisture in and preventing evaporation.


• Scalp lotion containing clobetasol for Inflammatory skin conditions of the scalp.

Warts

Keratoses

Unwanted facial hair

Local anaesthetic

haemorrhoids