Thursday, March 7, 2013

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.

1 comment:

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    TOSHIBA PLT-805AT

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