ACNE VULGARIS
Acne vulgaris is a common condition that mainly affects adolescents but may persist in to adulthood.It is a disorder of the pilosebaceous follicles characterised by papules,pustules,
nodules and special
lesions called comedones,with a
tendency to heal with
scars CLINICAL FEATURES: Acne is primarily a disease of the adolescent ,with 85% of all teenagers being affected to some degree. It
occurs with greatest frequency between the ages of 15 and 18 years in both sexes.Generally,involution of the disease occurs before the of 25,however great variation in the age at onset and of resolution occurs. Twelve percent of the women and 3% of men will continue to have clinical acne until 44 years of age. Neonatal acne is common condition that develops a few days after the birth and has a male sex preponderance and is characterised by a transient facial papules or pustules which usually clear spontaneously in a few days or weeks.
Acne commonly occurs on the face,neck,back,upper trunk and upper arms especially in persons with oily skin. On the face it frequently occurs on the cheeks and less frequently on the nose,chin and forehead. The basic lesion in acne is a follicular papule. Lesion in acne may be
inflammatory,noninflammatory and scars.
1.Noninflammatory lesions:
•open comadones (black head) are small papules with a dark central opening or pore filled with a black keratinin-melanin plug.
•Closed comadones(white heads ) are skin colored or yellowish papules,measuring about 1-5 mm size without a dark central opening or pore.It may require stretching of the skin to visualise
•
Post inflammatory lesions: Acne lesions tend to heal with scar ,perticularly the inflammatory lesions and nodules. The post inflammatory lesions include erythamatous macule or pigmented macule. The scars may also be elavated and hypertrophic and the tendency of scar
formation may be familial.
PATHOGENESIS OF ACNE: There are few important events in the causation of the acne namely
1.increase in the hormonal levels at puberty perticularly testosterone and dihydrotestosterone
2.this leads to increase in activity of sebaceous gland and increased sebum secretion ,which contains lipids.
3.abundance of lipid rich sebum leads to proliferation of bacteria called Propioniobacterium acne,the bacteria that produce lipase which lyses the triglycerides in the sebum and releases free fatty acids. The bacteria also leads to inflammatory reaction through release of cytokines.
4.free fatty acids cause increased follicular kertinisation and obstruction of hair follicle opening . Many patients also have inherent tendency for follicular obstruction.
5. Follicular obstruction leads to comedone formation.Inflammation leads to pustule formation.When untreated, the lesions progress to cyst formation and when the lesion rupture in to dermis ,they heal with different types of scars.
PREDISPOSING FACTORS FOR ACNE FORMATION:
1.Genetic factors such as family history of acne
2.Psychological stress and depression
3.Environmental factors such as high temperature and high humidity.
4.Cosmetics containing lanolin,petrolatum , vegetable oils etc.
5.Application of petroleum oils
6.Pressure from headbands and chin straps
7.Drugs such as Oral steroids ,contraceptive pills,testosterone,anabolic steroids such as danozol,stanozol etc. Iodides ,chlorides and bromides in cough syrup Antiepileptics such as carbamazapine,phenytoin,phenobarbitone etc. Antituberculous drugs such as ethionamide,isoniazide,rifampicin etc. Antidepressants such as lithium Cyclosporins B-vitamins such as vitamin B12 NOTE:Role of diet is controversial.Some patient often feel that certain diets excerbate the acne eventhough there is no scientific proof for this.
ACNE GRADING:
1.Mild (< 10 lesions per week)
2.Moderate (10-25 lesions per week)
3.Severe(>25 lesions per week)
However this classification does not apply to nodules as even one or two nodules may heal with distinguishing scar and hence needs aggressive treatment.
SPECIAL TYPES OF ACNE:
1
.Nodulocystic acne:Nodulocystic acne is a severe form of acne affecting the face ,chest and back.Nodulocystic acne is characterised by multiple inflammed and noninflammed nodules with a great tendency for formation of scars .It is more common in males and it needs aggressive treatment irrespective of number of lesions.
2.
Acne excoree :It occurs in emotionally disturbed patients with a tendency to pick or scratch the lesions.
3.
Acne medicamentosa(drug induced):It differs from acne vulgaris in not manifesting with comedones and lesions over atypical areas.
4
.Acne cosmetica: It is due to application of cosmetics containing lanolin,petrolatum etc.
5.
Acne conglobata: Acne conglobata is an uncommon form of acne in which there are large nodules ,pustules,with interconnecting abscesses and sinuses.The lesions which may be found in areas other than the typical areas.The lesions recur frequently and do not respond to routine treatment .
6.
Acne neonatorum:Acneiform eruption on the nose and cheeks in newborns or infants and is self limiting .
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