Acne vulgaris

• Stimulated by androgens

• Sebum: triglycerides, free fatty acids, wax esters, squalene, cholesterol

• Sebum functions:

– Waterproof

– mildly bactericidal

– mildly fungistatic

Sebaceous Glands

• Multilobed gland with lipid-containing cells

• Associated with hair follicles (face, behind ears, upper chest and back) or in the epidermis (eyelid, mucous membranes, nipple, genitalia)

Acne

• Inflammatory disorder of the pilosebaceous unit

• Affects mainly teenagers

• Starting between 12 and 14 years - earlier in females.

• It affects the sexes equally

• Has marked effects on QOL

• Clears by age 23-25 in 90%

Causes - multifactorial • Over-production of sebum

• Androgens excessive response to normal levels

• Occlusion of skin pores genetic, cosmetics

• Increased bacterial colonisation P.Acnes

• Genetics

• Diet dairy?

Presentation • On the face, shoulders, upper chest and back. • Seborrhoea (a greasy skin). • Open comedones (blackheads), because of the plugging by keratin and sebum of

the pilosebaceous orifice • or closed comedones (whiteheads), caused by overgrowth of the follicle

openings by surrounding epithelium. • Inflammatory papules, nodules and cysts • Depressed or hypertrophic scarring and post-inflammatory hyperpigmentation

can follow. • Conglobate (gathered into balls) is : a severe form of acne with all of the above

features as well as abscesses or cysts with intercommunicating sinuses that contain thick serosanguinous fluid or pus.

Variants of acne Neonatal acne • > 20%of healthy newborn babies between 2 weeks to 3

months of age • due to transplacental stimulation of a child’s sebaceous

glands by maternal androgens Infantile acne (rare) • at 3– 6 months of age and typically resolves in 12 months. Late onset • mainly in women and is often limited to the chin and

jawline • Nodular and cystic lesions predominate. • It is stubborn and persistent.

Acne fulminans. (rare) • conglobate acne + fever, joint pains and a high

(ESR).

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Mechanical : Excessive scrubbing, picking or the rubbing of chin straps or a fiddle can rupture occluded follicles.

Tropical : Associated with heat and humidity / mainly on the trunk and may be conglobate. Excoriated : This is most common in young girls. / Obsessional picking or rubbing leaves discrete denuded areas. Exogenous : Tars, chlorinated hydrocarbons, oils and oily cosmetics may induce comedone formation or precipitate inflammation around vellous hair follicles. Drug-induced : Corticosteroids, androgenic and anabolic steroids, gonadotrophins, oral contraceptives, lithium, iodides, bromides, antituberculosis and anticonvulsant therapy Polycystic ovarian syndrome. Congenital adrenal hyperplasia Androgen-secreting tumours

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Investigations • None are usually necessary. • Only a few laboratories routinely culture P. acnes

and test its sensitivity to antibiotics. • Cultures to exclude a pyogenic infection, an

anaerobic infection or Gram-negative folliculitis. • Any acne associated with virilization, needs

investigation to exclude an androgen-secreting tumour

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Treatment Topical • Gentle cleansing • Salicylic acid (comedones) • Benzoyl peroxide (inflammatory) • Vitamin A analogues (comedones)

– Tretinoin, isotretinoin, adapalene – Topical retinoids should not be prescribed for pregnant woman with acne.

• Azelaic acid (inflammatory, bactericidal) • Antibiotics *resistance*

– Clindamycin, erythromycin

Systemic • Erythromycin

– Erythromycin resistance in P.Acnes

• Tetracyclines – Oxytetracycline, tetracycline, lymecycline, doxycycline,

minocycline – Avoid in pregnancy and <9years – Minocycline side effects pigmentation & lupus-like syndrome

• Trimethoprim • Co-cyprindiol (dianette)

– Risk of VTE use only for 3 months after acne clears

Isotretinoin • Oral retinoid • Inhibits sebum excretion, inflammation and P.Acnes • Indication

– severe nodulocystic acne – scarring acne – non-responsive acne

• Side effects : – May flare on initiation – can use lower dose in first month(s) – Teratogenic – Risk of depression and suicidality – Dry skin, dry nose/lips/eyes – facial erythema – muscle aches – hyperlipidaemia – hair loss – Rare serious: loss of night vision, pancreatitis, hepatotoxicity, pseudotumour cerebri, hearing

loss

Treatment • Occasionally, an underlying cause is found; this should be removed or treated. • Local treatment for comedo-papular acne • both local and systemic treatments are needed for pustulocystic scarring acne

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