Studies indicate that white patients are more
likely to experience moderate to severe acne than
Patients tend themselves as nervous tend to
suffer more from acne
The peak of severity in females is 16-17 yrs and
in males 17-19 yr
Acne clears by age of 23 – 25 in 90% of patients
Some 5% of women and 1% of men still need
treatment in their thirties or even forties
Many factors combine to cause chronic inflammation of
blocked pilosebaceous follicles
The Pilosebaceous unit consists of cell lined hair
follicle containing rudimentary ―بدائي‖ vellus hair (the
fine, non pigmented hairs that cover most of the body)
and also consists of sebaceous gland.
The sebaceous gland’s secretions pass up ward
through the duct that carries the hair to the surface
Pilosebaceous density is greatest on the face,
upper neck and chest
At puberty, an abnormal cohesion takes place
between the epithelial cells that cover the unit,
this is called keratinization – sebum outflow
Also androgens provoke the sebaceous glands
to become multilobular which results in an
increased sebum output.
Bacteria infect the part and leads to
As sebum accumulates behind the keratotic
plug, dilation distorts the normal follicular
architecture, forming a microcomedo (a
small white head), …………………………..it
grows and become closed comedo known as
Increased and abnormal keratinization at the
exit of the pilosebaceous follicle obstructs the
flow of sebum, bacteria play a pathogenic
Propionibacterium acnes is a normal
commensal, it colonizes the pilosebaceous
ducts, breaks down the triglycerides, releasing
free fatty acids, produces substances
chemotactic for inflammatory cells and
induces the ductal epithelium to secrete pro
Follicular rupture, which occurs to an inflamed
pilosebaceous unit, results in formation of a papule,
pustule or cyst (nodule)
In summary there are four main factors responsible for the
pathogenesis of acne: Increased sebum production,
ductal hypercornification, bacterial proliferation
Whitehead: A condition of the skin characterized by a
small, firm, whitish, closed elevation of the skin. Also
known as a closed comedo; is a non inflammatory
Blackhead: A condition of the skin characterized by a
black coloration at the skin surface. Also known as an
open comedo; is a non inflammatory lesion.
Comedo (plural comedones)—A comedo is a sebaceous
follicle plugged with sebum, dead cells from inside the
sebaceous follicle, tiny hairs, and sometimes bacteria
Comedonal acne is the earliest clinical expression of
acne, is usually non inflammatory
Typically affects the central forehead, chin, nose and
This form of acne develops in the preteenage or early
teenage years as a result of increased sebum
production and abnormal desquamation of epithelial
Colonization by P. acnes has not yet occurred, so
there usually are no inflammatory lesions. At this
stage, therapy should be focused on prevention,
minimizing formation of new comedones and the
proliferation of P. acnes.
papule is caused by localized cellular
reaction to the process of acne
Most patients with acne present with
comedones and papules on the face and
Their formation begins with
noninflammatory comedonal acne
progressing to a small number of
inflammatory lesions on the face, which
then evolve into a more generalized
eruption first on the face and then trunk.
Papule; Circumscribed raised lesion <1cm in diameter
This photo shows papules and comedones on the face of an acne patient
dome-shaped, fragile lesion containing pus
that typically consists of a mixture of white
blood cells, dead skin cells, and bacteria
A pustule that forms over a sebaceous
follicle usually has a hair in the center
Acne pustules that heal without progressing
to cystic form usually leave no scars
Pustules; Circumscribed raised lesions containing cloudy fluid. >0.5cm in diameter, Not
papules and comedones on the face of an acne patient
Nodular acne is a severe form of acne
that may not respond to therapies other
Larger than a pustule, may be severely
inflamed, extends into deeper layers of the
skin, may be very painful, and can result in
Cysts and nodules often occur together in a
severe form of acne called nodulocystic
Nodule; Circumscribed raised lesion >1cm in diameter
• Lesions are limited to the face, shoulders, upper
chest and back
• Seborrhea (greasy skin) is often present
• Open comedones (black heads) due to plugging by
keratin and sebum of the pilosebaceous orifice
• Closed comedones (white heads) due to accretions
of sebum and keratin deeper in the pilosebaceous
ducts are always evident
• Scarring may follow
•Conglobate acne is severe with many abscesses and
•Acne fulminans is a type of conglobate acne
accompanies by fever joint pains and a high
erythrocyte sedimentation rate
•Exogenous acne may be caused by tars, chlorinated
hydrocarbons, oils and oily cosmetics; comedones
dominate the clinical picture
•Drug induced acne may result from treatment with
corticosteroids, androgenic steroids, lithium, oral
contraceptives and anti convulsant therapy.
Severity rating for acne
Type 1: comedones only, fewer than 10 lesions on the
face, no lesions on the trunk and no scarring
Type 2: papules, 10 to 25 lesions on the face and trunk,
Type 3: pustules, more than 25 lesions, moderate
Type 4: nodules or cysts, extensive scarring
Premenstrual exacerbations of acne are very
common, with about 70 percent of women frequently
experiencing flare-ups of acne two to seven days
before the onset of menses and gradual improvement
at the beginning of the next menstrual cycle
Certain cosmetic ingredients, such as lanolins,
petroleum bases, cocoa butter and pomades, can
precipitate acne development
Medications That Cause Acne
•Testosterone, a male hormone, can induce acne in females and in pre-adolescent children.
•Gonadotrophin that may be prescribed in certain pituitary disorders can indirectly induce acne by
stimulating testosterone production.
•Anabolic steroids are masculinizing hormones that can provoke or aggravate acne.
•Corticosteroids, taken orally or applied topically to the skin, may cause a degeneration of the
epithelial lining of sebaceous gland
•Individuals with severe epilepsy often have many endocrine (hormonal) problems, including
abnormal testosterone secretion.
•Isoniazid, the most widely used drug for treating tuberculosis, has been associated with
precipitation or aggravation of acne in small numbers of patients.
•Acne precipitation or aggravation is one of the dermatologic side effects of lithium, a medication
prescribed in the treatment of bipolar disorder.
•Dermatologic reactions, including precipitation or aggravation of acne, are frequently seen in post-
transplant patients who must take cyclosporin to prevent organ rejection. Since cyclosporin cannot
be discontinued in a post-transplant patient, the side effect of acne should be treated by a
•Medications containing iodine or bromine can cause acne-like eruptions. These medications are
much less common today than in earlier years, but some are still in use. In the United States today, it
is probably more likely to see acne-like outbreaks resulting from heavy consumption of iodine-
containing health foods such as kelp. An acneiform eruption caused by eating large amounts of kelp
is seen in this photo:
Goals of therapy
Preventing pitting or scarring
Limiting psychosocial distress
Good skin hygiene is a basic tenet in acne
Twice-daily cleansing with warm water and a mild
soap can effectively remove excess sebum and
improve skin appearance.
Aggressive skin washings will not alter the course
of acne and may actually aggravate acne by
promoting the development of inflammatory lesions.
Abrasive or antibacterial cleansers are not
recommended, and squeezing or picking of acne
lesions should be discouraged without the use of
Drugs, cosmetics or other known precipitants also
should be avoided.
Retinoids work to normalize follicular keratinization;
Isotretinoin and hormone manipulations decrease
Antibiotics and benzoyl peroxide target P. acnes.
Antibiotics and retinoids also are used to prevent
inflammation associated with bacterial colonization,
Topical therapy generally is preferred over systemic
agents for mild to moderate acne.
Topical antibacterial agents,
such as benzoyl peroxide,
Comedolytic agents, such as
salicylic acid and tretinoin
(Retin-A), that unplug follicles
with their exfoliative effects.
Is one of the most effective agents against acne
vulgaris, causing mild desquamation and
comedolysis by increasing epithelial cell turnover
and unblocking pores.
Its main effect is due to its antibacterial property
of releasing free radicals and oxidizing bacterial
protein. While benzoyl peroxide minimally reduces
sebum production, it significantly lowers FFA
A mild comedolytic agent agents with mild
Combination of these agents are considered
It may actually enhance absorption of other
topical agents when used concurrently.
A recent review shows that salicylic
acid pads are safe, effective and superior
to benzoyl peroxide in preventing and
clearing both types of acne lesions.
Salicylic acid, and Sulfur
Have been used successfully to treat acne
for many years.
Tretinoin (Retin-A(R)), also called all-trans-
retinoic acid, is the naturally occurring form
of vitamin A acid and is considered the most
effective topical comedolytic agent.
Retinoids indirectly reduce P. acnes
colonization by decreasing sebum
production, a requisite for bacterial survival.
Vitamin A analogues
They also decrease horny cell cohesiveness
by stimulating epidermal cell turnover and
These actions unplug follicles, which
ultimately prevents microcomedone formation
Considered highly effective agents because
their pharmacologic activities target each of
the four known pathogenic factors.
Adverse effects with retinoid therapy occur
in nearly all patients, with dryness, redness
and peeling at the site of application topping
Cont…… Vitamin A analogues
Exposure to sunlight can significantly
intensify irritation to the skin. If sun exposure
is unavoidable, patients should use a
sunscreen with an SPF of at least 15.
Topical tretinoin may further darken skin in
patients with dark complexion.
Patients should be made aware that
improvement may take six to 12 weeks, and
that flare-ups of acne can occur during the
first few weeks of therapy.
Cont…… Vitamin A analogues
Topical antibiotics are effective in treating
mild to moderate inflammatory acne, and they
offer the advantage of direct topical application
and less systemic absorption.
The side effects are minimal, the most
common being mild burning or irritation.
They also can be used as an adjunct therapy
in nodulocystic acne.
Available in a 1% solution, lotion or gel (Cleocin-
Various studies show it to be as effective as
topical erythromycin or oral tetracycline.
A 12-week course of 1% clindamycin solution
twice daily showed significant reduction in the
number of inflammatory and noninflammatory
Rare cases of pseudomembranous colitis have
been reported with topical use of clindamycin.
Considered to be the safest acne agent to use
It is available in a 2% solution (Eryderm),
њGels usually have a high alcohol content that allows for
better absorption, but they also can be more drying.
Therefore, a cream or ointment may be better tolerated in
patients with sensitive skin.
њGels are useful for patients with oily skin.
њFor optimal results, the entire susceptible area, not just
the lesions, should be treated.
Vehicle consideration is important in topical
Patients with moderate to severe inflammatory
acne may require oral antibiotics in addition to
Systemic antibiotics can achieve a more rapid
clinical improvement, usually two to six weeks,
with maximal clinical improvement in three to
The disadvantages of oral antibiotics, though,
lie in their side effects: gastrointestinal distress
and vaginal candidiasis.
Twice-daily dosing of systemic antibiotics
normally improves compliance, is usually as
effective as more frequent dosing and may be
used for chronic therapy
Long-term use of antibiotics has been found to
be safe and effective in treating acne
Cont…… Pustular acne
Generally considered the first choice of oral
agents in pustular acne due to its documented
effectiveness and low cost
With a usual starting dose of 250 mg four times
daily or 500 mg twice daily, 250 mg twice daily for
four months also was found to be safe and
effective in treating papulopustular acne, with 95
percent of patients showing clinical improvement
The antibiotic of choice in acne if cost were not a
It is highly effective in acne treatment due to its
lipid solubility and ability to penetrate the
Minocycline is used in patients with tetracycline-
resistant acne and achieves good absorption even
when administered with food.
Doxycycline Is less expensive than minocycline and its high lipid
profile also makes it a good agent in acne treatment
The usual dose is 100 mg once daily, and side effects include
photosensitivity and gastrointestinal distress
The usual dose of erythromycin is similar to that for tetracycline.
P. acnes resistance to erythromycin is more common than with
tetracyclines according to various studies and gastrointestinal side
effects limit its use.
Erythromycin, though, has the advantages of not inducing
photosensitivity and not interacting with antacids and dairy
Trimethoprim-sulfamethoxazole is reserved for
severe cases of acne refractory to other antibiotics
Therapy initiated at one double-strength tablet of
trimethoprim - sulfamethoxazole daily
Potential side effects include rash, photosensitivity,
dizziness and Steven-Johnson's syndrome ―SJS, is an extreme
allergic reaction, usually to a drug, but also to certain bacterial and viral
infections‖, a severe eruption reaction.
Despite the relative success of antibiotic therapy, many patients do
not achieve full suppression of inflammatory lesions with continued
antibiotic usage, explanations for which include differences in
dosage regimens, drug absorption and patient compliance
Resistance to P. acnes should be considered in patients whose
response decreases with therapy that previously was successful
It did not become a problem until the mid 1970s, despite nearly two
decades of antibiotic usage
British studies reveal that resistance to erythromycin is most
prevalent, with the majority of the strains also being resistant to
clindamycin. Cross-resistance between tetracycline and doxycycline
also has been reported
Failure of antibiotic therapy
Treatment options for these patients include isotretinoin,
steroid injections and hormone therapy
Systemic antibiotics can also be used in treating cystic
acne, but long-term use may be limited by resistance and
adverse effects, including photosensitivity, gastrointestinal
disorders and vaginitis
Is a synthetic 13-cis-isomer of tretinoin, usually
more effective than tretinoin and available as 10-,
20- or 40-mg oral capsules
It is the only systemic agent that decreases
sebum production and reverses the abnormal
epithelial desquamation process
It also can decrease the population of P. acnes in
the sebaceous follicle, making it the treatment of
choice for patients with severe nodulocystic acne
The initial dose of isotretinoin is 0.5 to
1.0 mg/kg or 40 mg to 80 mg per day, with
a usual course of therapy of four to five
Transient exacerbation of acne may occur
during the first few weeks of therapy, but most
patients respond well over time
Usually no further therapy is needed.
Satisfactory response rate has been as high as
90 percent with a low relapse rate of 31 percent
at nine years
Adverse effects of systemic isotretinoin include
cheilitis (lip inflammation), dry skin, pruritus,
photosensitivity and mild to moderate
Dryness of the eye also can occur, so
patients wearing contacts should be warned
not to wear them
Pseudo-tumor cerebri (benign intracranial
hypertension) can occur if isotretinoin is taken
concurrently with tetracycline
Isotretinoin is contraindicated throughout
pregnancy due to teratogenic effects
Contraception should be used throughout
therapy and continued for at least one month
after the last dose
Due to these serious adverse effects and
overuse potential, strict guidelines exist for
Not only does squeezing pimples cause further
infection and inflammation, but it can also spread the
bacteria (and the acne) from one pore to the next.