Acne vulgaris
Objectives:Explain etiology and Pathogenesis of Acne vulgaris.
Label different types of Acne.
List available modalities to
treat acne.
Compare acne to rosacea.
Definition
Acne vulgaris is a chronic inflammatory disease of pilosebaceous unit. It is a polymorphic disorder characterized by formation of comedones -which are either close (white heads) or open (black heads) - , papules, pustules, nodules and pseudocysts. In some cases, it is accompanied by scarring.The sites of predilection of acne vulgaris are the face, upper trunk and upper arms.
Acne is a condition that affect adolescent commonly and usually resolved by the mid twenties and it is of multifactorial aetiology .
The Pilosebaceous Unit (PSU):
Pilus, being the Latin for hair and sebum, the Latin for grease. The PSU. is composed of : the hair follicle and the attached sebaceous gland which opened to the hair follicle's infundibulum. The SG.s are androgen dependant, their development and function. At puberty, as a result of increased androgen out put the SG.s become greatly enlarged and their activity increased.
The etiology and Pathogenesis of Acne vulgaris:
Four major factors are involved in the pathogenesis of Acne:
I Increase sebum production.
II- Obstruction of the pilosebaceous duct (comedogenesis).
III- Colonization of the duct with Propionibacterium acnes (P.acnes).
IV- The production of inflammation .
The sebaceous gland converts inactive testosterone and its precursors into active dihydrotestosterone (DHT) mainly by type 1-5α reductase enzyme. DHT then bind specific cytoplasmic receptors in the SG. to stimulate the production of sebum. In acne, the sebaceous glands may respond excessively to what are normal levels of these hormones (increased target organs sensitivity). This may be caused by 5α reductase activity being higher in target sebaceous glands than other parts of the body . Most acne patient secrete an average more sebum than normal subjects;and this sebum is different from normal by being deficient in linoleic acid at the same time microcoedons (which are the primary lesions of acne composed of dead coneocytes,sebum &depris that form a plug blocking the opening of sg. duct) are formed and plug enlarges behind a very small follicular orifice and become visible as closed comedone (firm white papule or whitehead). An open comedon (black head) occurs if the follicular orifice dilates . The sebum that passes through the follicular canal will be hydrolyzed by P.acnes lipase enzyme to liberate free fatty acids (FFA.s) which are comedogenic, Irritant and can cause inflammation in and around the hair follicles .
Later in the inflammatory process, the duct of SG. ruptures and the contents get to the dermis resulting in more severe inflamation .
Other factors affecting the pathogenesis:
A. Endogenous factors
Genetics:Family history of acne was found to be positive in 46%
Menstruation:63% of women have flare up of acne 2-7 days premenstrually.
3.Stress and anxiety: Substance P which is produced during stress, stimulate SG.
B- Exogenous factors:
1.Hot humid environment and sweating: causes deterioration of acne
2.Diet: The relationship between acne and dietary habits are so controversial therefore no food is exceptionally forbidden .
.Occupation: occupations such as those dealing with oil halogenated carbons steam cleaning may devlop acne .
Clinical Presentation of Acne:
Prevalence: Acne is one of the most frequent reason for seeing a dermatologist . Prevalence reaching over 90% of males and 80% of females.
Age of onset: The condition usually starts in adolescence. Acne develops earlier in females than in males that may reflect the earlier onset of puberty . Mean age at onset of acne was 12 1 years in girls and 15 1 years in boys.
Sites of distribution:
Acne predominantly affects the face (99%) and to lesser extent occurs on the back (60%) and chest (15%) upper arms are also affected .
The types of lesions in Acne:
A Non inflammatory lesions: (comedones) which consist of:
White heads (closed comedones).
Black heads (open comedones).
B Inflammatory lesions include:
The superficial lesions are usually papules and pustules.
The deep lesions are deep pustules, nodules and pseudocysts &
Sinuses
Symptoms: Acne is aesthetically and physically unpleasant..
Acne Scarring: Scar, by definition means replacement by fibrous tissue of another tissue that has been destroyed by injury or disease.
Types of acne scarring:
Atrophic scars.
Ice pick scars: They are small 1-2 mm size triangular indentation .
Hypertrophic scars: These type of scars show increased collagen. They are elevated but not extend beyond the extent of original inflammation .
5- Keloid scars: They are the least common and mostly occur on the trunk. they are elevated and they do extend beyond the area of original inflammation .
Persistent post inflammatory hyper pigmentation is a common feature associated with scarring acne in pigmented skin and may be more disabling than the original disease. Finally, acne scarring can cause long-term psychic trauma for the sufferer.
Other Types of acne:
1- Neonatal acne: That is limited to the neonatal period. Under the effect of maternal androgen transient facial papules appear & resolve without treatment .
2-Late onset acne: is acne that starts at mid twenties (over 25 years) occur mainly in women and is often limited to the chin, nodular and cystic lesions predominate. It is stubborn and persistent .
3-Persistent acne: acne that persist beyond the age of 25 years most of them have strong family history of persistent acne.
4-Acne astevalis: A rare form of acne starts in spring progress during summer and resolve completely in the fall. .
5-Cosmetic Acne: Acne that results from use of comedogenic cosmetics occurs in the perioral area of adult females
6-Pomade acne: consist of non inflamed lesions around the forehead where greasy pomades may extend from the hair to the nearby area .
7-Acne venenata: Results from Contact with chemicals s.a. chlorinated hydrocarbons, cutting oils, petrolatum oil and coal tar .
8-Drug induced acne: Many drugs can induce acne or acne form rash such as androgens including anabolic steroid, gonodotrophins, oral contraceptives, Lithium, Iodide, Bromide and topical and systemic glucocorticoid, they give monomorphic acne in which all lesions are at the same stage of development
9-Endocrine acne: Acne that clinically manifest endocrine disease such as cushing disease, adrenogenital syndromes, polycystic ovarian syndrome .
10-Acne conglobata: It is severe form with all features of acne as well as abscesses or cysts with intercommunicating sinuses that contain their serosanguinous fluid or pus. On resolution, it leaves deeply pitted scars or hypertrophic scars, some time joined by keloidal bridges .
11-Acne fulminans: A rare ulcerative form of acne with an acute onset and systemic symptoms including fever, weight loss and myalgia .
12-Gram negative folliculitis: This is a complication of long term treatment of acne with antibiotics. It presents as sudden eruption of multiple small follicular pustules. It is caused by replacement of Gram- positive flora of the facial skin by Gram-negative bacteria ..
13-Acne excori (excoriated acne): This variant occurs predominantly in young females who pick and squeeze acne lesions, resulting in more inflamed crusted even ulcerated papules .There is often some psychological problems. The disease merges into dermatitis artifacta.
Complications of acne vulgaris:
Psychological impact of acne because of its disfiguring effect, and it ranges from mild discomfort to depression and even suicidal ideas
Scarring, that may be associated with hypo-, hyperpigmentation or blue-grey discoloration .
Differential diagnosis of acne:
1-Rosocea.
2-Perioral dermatitis.
3-Psudofolliculitis barbae and folliculitis barbae .
4-Pitrosporum folliculitis. .
5-Acneform drug eraption.
6-Acneform2syphilis.
Investigations in Acne patients:
Acne is usually diagnosed on clinical bases and no investigations are routinely required but in certain conditions, Whenever acne is associated with virilization,(s.a hirsuitism, irregular menses) it needs investigations to exclude poly cyctic overy and androgen secreting tumors of adrenals or gonads.
Tests include:
Plasma free testosterone.
Sex-hormone binding globulin ( SHBG) .
LH and FSH .
LH : FSH ratio greater than 2:3 is often seen in patient with polycystic ovarian disease .
Ultrasound examination of ovaries and adrenals.
Treatment of Acne:
Treatment of acne falls into three types of measures, which are:
A-General measures.
B-Topical treatment.
C-Systemic therapy.
The choice of therapy is determined by the severity, extent of the disease, presence of scarring, psychological effects of the disease and the degree of success of previous treatments. In general, patients with mild acne usually receive topical therapy alone. Those with moderate acne receive topical and oral therapies, while those with severe acne are to be given isotretinoin unless it is contraindicated .
A - General measures:
General measures include gentle cleansing with soap and water. affected person should be told to avoid comedogenic applications. In addition, they are often depressed and need reassurance .
B- Topical treatments:
Topical treatment can be subdivided into two categories:
1- Those directed towards microorganisms.
2- Those directed towards comedogenesis.
1- Topical treatments directed towards microorganisms:
Topical antibiotics:such as erythromycin (2% gel or cream), clindamycin (1% lotion) applied twice daily.
Benzoyl peroxide:
Benzoyl peroxide is available in concentrations of 2.5% , 5% and 10% inform of gel or lotion , either alone or in combination with antibiotics such as erythromycin
2-Topical treatment directed towards comedogenesis:
Retinoids: Retinoids are vitamin A derivativesthey affect multiple pathogenic mechanisms contributing to the development of acne, they have:
1- Anti-seborrheic effect.
2- Anti-comedonal effect:
3- Inhibit the growth of P. acnes
4- Anti-inflammatory effect
Tretinoin may be used as solution, cream or gel. It is available in 0.025% , 0.05% and 0.1% concentration . Tazarotene (0.1% gel) applied once daily. Topical retinoid should not be prescribed to pregnant women with acne .
Adapalene: Adapalene (0.1% gel) have retinoid like activity .
Azelaic acid: dicorboxylic acid, supplied in form of cream with 20% concentration . It can be applied twice ..
C) Systemic Treatment of acne:
Systemic treatment of acne can be subdivided into three categories:
1-Those directed against microorganisms (Antibiotics).
2-Those directed against comedogenesis and seborrhea (retinoids).
3-Those acting on hormonal bases (antiandrogens).
Systemic antibiotic:
Moderate or severe inflammatory acne, acne resistant to topical treatment or acne that covers large area of the body may be best treated with oral antibiotics. The improvement usually seen after 4-8 weeks . The antibiotics are not to be used for less than 3 months .
Tetracycline: 250 mg four times daily
Doxycycline: It is usually given in a dose of 100 mg once or twice daily .
Minocyclin: The usual dose is 50-100 mg once or twice daily
Erythromycin and Azithromysin: Erythromycin 250-500 mg twice to four times daily especially for pregnant women.
Clindamycin: In a dose of 75-150 mg,
2- Systemic Retinoids:
. Indications for systemic retinoids in acne include the following:
1- Severe acne.
2- Moderate acne unresponsive to conventional therapy.
3- Acne in patients prone to scarring.
4- Severe depression or dysmorphophobia.
5- High sebum excretion rate.
6- Some unusual variants, such as acne fulminans, gram-negative folliculitis .
usual dose of isotretinoin is 0.5-1 mg /kg/day for three to six months course.
The most remarkable side effect of isotretinoin is its potential teratogenisity. Other side effects include mucocutanceous effects such as cheilitis, conjunctivitis, epistaxis and pruritus, systemic side effects such as hypertrigleceridemia, increased intracranial pressure arthralgia and myalgia .
3- Hormonal therapy:
Hormonal therapy is an option of treatment when acne is not responding to conventional therapy. If there are signs of hyperandrogenism, an endocrinal evaluation is indicated.
Antiandrogen therapies can be classified into:
A- Androgen production inhibitors: such as glucocorticoid and oralContraceptive.
B-Androgen receptor blockers: such as cyproterone acetate, spironolactone and flutamide.
C- Androgen activating enzyme inhibitors: such as finastride .
A- Androgen production inhibitors:
Glucocorticoids: Low dose of prednisolon 2.5-5 mg/day at bed time to suppress adrenal androgen is an option ..
Oral contraceptives: Oral contraceptives suppress ovarian and adrenal androgen.Low dose oral contraceptives containing a non-androgenic progesterone can be effective. Beneficial effect can be noted only after several months of therapy and in general, prolonged treatment is needed for control of persistent acne in females .
B- Androgen receptor blockers:
Cyproterone acetate (CPA): It can be given in a dose of 2-100 mg per day, and most commonly used for females in form of an oral contraceptive with ethinyl estradiol ( ethinyl estrodiol 35 mg plus 2 mg CPA ) .
Spironalactone: The recommended dose of spironolactone is 50-200 mg. Pregnancy should be avoided during treatment with spironalactone because of potential abnormality of male fetal genitalia.
Flutamide: Flutamide is a very potent antiandrogen. It can be given in a dose of 250 mg twice daily in combination with oral contraceptives .
C-Androgen activating enzyme inhibitors:
The 5-alpha reductase enzyme converts testosterone to dihydrotestosterone, and it has two isoenzymes; type 1 and type 2, type 1 is found primarily in the sebaceous glands. Therapies that block the activity of these enzymes such as finastride may be useful in the treatment of acne .
Treatment of acne scars:
1-Scars resulting from tissue loss: such as atrophic and ice pick scars. with dermabrasion . augmentation techniques.
2-Scars resulting from tissue excess: such as keloid and hypertrophic scars: surgery, Intralesional corticosteroids, pressure therapy.
Rosacea
Rosacea (Latin: like roses) is a chronic inflammatoy disorder of the facial pilosebaceous units, coupled with an increased reactivity of capillaries, leading to flushing and telangiectasia.Age of incidence between 30 to 50 years,
Sex Females predominantly;but rhinophyma occurs mostly in males
Race Celtic peoples (skin phototypes I and II) less frequent or rare in pigmented (brown and black) peoples
DISTRIBUTION Characteristic is a symmetrical localization on the face
Skin Symptoms/ Patients are concerned about their cosmetic facial appearance; Flushing, feeling of heat in the face.
Stages of Evolution //
patients with rosacea usually have a long history of episodic reddening of the face (flushing) in response to heat stimuli in the mouth (hot liquids), spicy foods; alcohol (cold or hot), exposure to sun, heat and emotional stress.
Stages
*Episodic erythema, flushing and blushing
Stage I: Persistent erythema with telangiectases
Stage II: Persistent erythema, telangiectases, papules, tiny pustules
Stage III: Persistent deep erythema, dense telangiectases, papules, pustules, nodules; marked sebaceous hyperplasia edema of the central part of the face "glandular rosacea"
Chronic rosacea can be associated with marked sebaceous hyperplasia and lymphedema, causing disfigurement of the nose {Rhinophyma (enlarged nose) }
Eye Lesions/// Red eyes as a result of chronic blepharitis, conjunctivitis, and episcleritis. Rosacea keratitis is a problem because corneal ulcers may develop.
Differential Diagnosis
Acne, (note: in rosacea No comedones )Perioral dermatitis, folliculitis, and SLE
Dermatopathology
1-Dilated capillaries.
2-Marked sebaceous gland hyperplasia
3-Inflammatory infiltrate with foci of neutrophils within the follicle
4 -epithelioid granuloma without caseation,
Course
Prolonged. Recurrences are common. After a few years, the disease tends to disappear spontaneously.
Management
Reduction of alcoholic and hot beverages may be helpful.
Topical :\Metronidazole gel or cream, 0.75 %, twice daily or
Topical antibiotics (e.g., erythromycin gel).
Systemic: oral antibiotics: Tetracycline, 250mg 4td. until clear; then gradually reduce to once-daily doses of 250 to 500 mg. Minocycline and doxycycline, 50 to 100 mg twice daily, are alternative antibiotics.
Oral Isotretinoin is an alternative in individuals with severe
disease (especially with seborhoea) . A low-dose regimen of 0.1 to 0.2 mg/kg of body weight per day is effective in most
patients but occasionally 1 mg/kg may be required.
Rhinophyma, is treated successfully by surgery or laser surgery.
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