Acne Vulgaris

Incidence:

Occurs mostly in teenagers.

Peak: Late teenagers but may persist till third decade and beyond especially in females.

Etiology:
Elevated sebum excretion:

• Sebum excretion is necessary for the development of acne but is not sufficient to cause acne on its own.
• The main determinants of sebum excretion are hormonal, which accounts for the onset of acne in the teenagers. 
• Androgens and  progestogens increase sebum excretion but estrogens reduce it.

Propionibacterium acnes

• It colonises the pilosebaceous ducts and acts on lipids to produce a number of pro-inflammatory factors.
• Occlusion or blockage of the pilosebaceous unit.

Clinical features

Site: Usually limited to the face, shoulders, upper chest and back.
Greasy skin

• Open comedones (blackheads) due to plugging by keratin and sebum of the pilosebaceous orifice,
• Closed comedones (whiteheads) due to accretions of sebum and keratin deeper in the pilosebaceous ducts are evident.
• Inflammatory papules, nodules and cysts may occur with some lesion.

The lesion may be followed by scarring.
Mild form: 

• Dominated by presence of comedones.
• May be due to exogenous substances like oily cosmetics, chlorinated hydrocarbons, tars, etc
• Pustular rash may also be seen in those treated with steroids, lithium, OCP and anticonvulsants.

Moderate or Severe form: 
May have systemic disorder. E.g- polycystic ovarian disease, Androgen secreting tumors

Clinical variants of Acne:

1. Conglobate acne: 
severe acne with many abscesses and cysts, marked scaring and sinus formation.

2.  Acne fulminans: 
severe acne accompanied by fever, joint pains and markers of systemic inflammation ( raised ESR)

2.  Acne excoriee: 
effect of scratching or pricking, mostly seen on the face of teenage girls with acne.

3.  Infantile acne: 
Rare. It is due to sebotropic effects of maternal hormones on the infant.

Investigation: Rarely required.
 It is important to enquire about the details of previous treatments and their duration.

Treatment:

1. Topical benzoyl peroxide: 

• Benzoyl peroxide is a broad spectrum bactericidal agent which is effective due to its oxidizing activity.
• The drug has an anti-inflammatory, keratolytic, and comedolytic activities, and is indicated in mild-to-moderate acne vulgaris.

Adverse effect:
It can induce irritant dermatitis with symptoms of burning, erythema, peeling, and dryness.This occurs within few days of therapy and mostly subsides with continued use.

2. Topical retinoids:

• Topical retinoids target the microcomedo–precursor lesion of acne. There is now consensus that topical retinoid should be used as the first-line therapy, alone or in combination, for mild-to-moderate inflammatory acne and is also a preferred agent for maintenance therapy.
• It targets the abnormal follicular epithelial hyperproliferation, reduces follicular plugging and reduces microcomedones and both noninflammatory and inflammatory acne lesions.

Adverse effect:
The main adverse effects with topical retinoid is primary irritant dermatitis, which can present as erythema, scaling, burning sensation and can vary depending on skin type, sensitivity, and formulations.

3- Topical Anti-biotics therapy:

  Local antibiotics: Clindamycin or Erythromycin. 
Clindamycin and erythromycin were both effective against inflammatory acne in topical form in combination of 1–4% with or without the addition of zinc.
  
 Oral antibiotics: 

• Oxytetracycline 1.5g per day on empty stomach. 
• If the response is inadequate: 
• Minocycline ( both must be continued till 3 months to see if the antibiotics have worked or not)
•  If little response after 3 months treatment: Erythromycin 1g/day.
• Topical clarithromycin, azithromycin, and nadifloxacin are available in India, but trials for their efficacy and safety are lacking.
• In women, oestrogen containing OCP can be used as a adjunct in therapy. ( oral estrogen reduces sebum production)

Adverse effect: Side effects though minor includes erythema, peeling, itching, dryness, and burning, pseudomembranous colitis which is rare, but has been reported with clindamycin.
A most important side effect of topical antibiotics is the development of bacterial resistance

4-  If these topical agents fails to produce an adequate clinical response within 3-6 months;
Systemic retinoids— Isotretinoin (decreases follicular keratinization, Sebum production, bacterial count)

 Physical Treatment: 

a) Comedones:
Both open and closed comedones can be removed mechanically with comedone extractor and a fine needle or a pointed blade.

b) Active deep inflammatory lesions:
Aspiration of deep inflamed lesion may be needed in few cases which are followed by IL steroid injection in cysts and sinus tract.

Rosacea

It is a chronic disorder affecting the facial convexities, characterized by frequent flushing, persistent erythema and telangiectasia, interspersed by episodes of inflammation during which swelling, papules and pustules are evident.

Clinical features

• The areas characteristically affected are the central convex areas of the face (nose, forehead, cheeks and chin) . Occasionally, the scalp, upper chest, back and even the limbs may be involved. 
• In cases of rosacea showing the classical pattern of progression, the onset is most often marked by vascular changes, notably episodic flushing usually unaccompanied by sweating.
• Erythema, which is often accompanied by a burning sensation, gradually becomes more persistent, is easily triggered by minor irritants, and is associated with increasingly prominent telangiectasia.
• More advanced cases show follicular and nonfollicular papules and pustules, without comedones, followed by persisting tissue thickening due to oedema, fibrosis and glandular hyperplasia, leading ultimately to a peau d’orange appearance and phymas.

Factors which trigger flushing: Include emotion and stress, hot drinks, alcohol and other vasodilating drugs, and spicy food. 
Aggravating factors: Include the use of topical steroids on those occasions when they are used (usually in error) to treat rosacea.

• Sun exposure may worsen or improve rosacea.
• Rhinophyma, with erythema, sebaceous gland hyperplasia  and overgrowth of the soft tissue of the nose, is sometimes associates.
• There may be complications like blepharitis and conjunctivitis.

Treatment

• Oral oxytetracycline can be used for the pustular component of rosacea.
• Topical metronidazole can also be used.
• Erythema and telangiectasia don’t respond to antibiotic therapy.

Skin Disorder-Psoriasis

What is psoriasis?
Psoriasis is an immune-mediated disease that affects the skin.It is typically a lifelong condition. No complete cure for the psoriasis.

Pathogenesis:

• Psoriasis occurs when the immune system mistakes a normal skin for a pathogen and sends out wrong signals that cause overproduction of new skin cells.
• Psoriasis is a long term(chronic) skin problem that causes skin cells to grow too quickly and makes thick, white, silvery or red patches of skin. Normally skin cells grow gradually and flake off every 4 weeks. New skin cells grow to replace the outer layers of the skin as they shed. But in psoriasis  new skin cells move rapidly to the surface of the skin in days rather than week.

Types:
Psoriasis is of 5 types;
1-Plaque
2-guttate
3-inverse
4-pustular
5-erythrodermic
 The most common type is plaque usually appears as red and white hues of scaly patches.

What are the Causes?

• Psoriasis occur when immune system overreacts, causing inflammation and flaking of skin.
• In cases are related to families.Research shows that large number of families are affected by psoriasis and it may pass from parents to children.
• Causes also include; cold dry climate, stress and dry skin. Certain medicines e.g; nonsteroidal anit-inflammatory drugs(NSAIDs).
• Smoking: especially in women.and can make it worse if somebody already have it.
• Psoriasis is not contagious.However, psoriasis has been linked to an increased risk of stroke and treating high blood lipid levels may lead to improvement.

Signs & Symptoms:

• Psoriasis can be mild, with small areas of rash. 
• When psoriasis is moderate or severe, the skin gets inflamed with raised red areas topped with loose, silvery, scaling skin.
• If psoriasis is severe, the skin becomes itchy and tender. And sometimes large patches form and may be uncomfortable. The patches can join together and cover large areas of skin, such as the entire back.

Psoriatic arthritis:
In some people, psoriasis causes joints to become swollen, tender, and painful. This is called psoriatic arthritis.
This arthritis can also affect the fingernails and toenails, causing the nails to pit, change color, and separate from the nail bed. Dead skin may build up under the nails.
Symptoms often disappear (go into remission) even without treatment and then return (flare up).

How to Diagnosis?

• Psoriasis diagnosis is usually based on appearance of the patches on skin, scalp or nails.

• KOH test can help too in ruling out fungal infection.

> No special test is needed for psoriasis.

Treatment

• First step, medicated ointments or creams+shampoo called topical treatments, are applied to the skin. If topical treatment fails to achieve the desired goal, then the next step would be to expose the skin to ultraviolet (UV) radiation. This type of treatment is called phototherapy.
• The third step involves the use of medications which are taken internally by pill or injection. This approach is called systemic treatment.

> Phototherapy in the form of sunlight has long been used effectively for treatment. Wavelengths of 311–313 nm are most effective and special lamps are available for this purpose. The exposure time should be controlled (15-30minutes) to avoid over exposure and burning of the skin.
> Vitamins A & D also helps to improve the disease condition.