Retinoids have both comedolytic and anti-inflammatory properties
Available preparations – Tretinoin, Isotretinoin, adapalene, and tazarotene
Anti-acne Actions of Topical Retinoids :
1. Inhibit the formation of and reduce the number of microcomedones (precursor lesions).
2. Reduce mature comedones.
3. Reduce inflammatory lesions.
4. Promote normal desquamation of follicular epithelium.
6. Likely to enhance penetration of other drugs.
7. Likely to maintain remission of acne by inhibiting microcomedone formation.
2) Benzoyl Peroxide
The most common topical medication prescribed; also readily available over-the-counter; available in creams, lotion, gels, washes, and pledgets in strength 2.5% - 10%.
A powerful antimicrobial agent through decreasing both the bacterial population and the hydrolysis of triglycerides.
Can produce significant dryness and irritation - Allergic contact dermatitis.
Of significance, bacteria are unable to develop resistance to benzoyl peroxide, making it the ideal agent for combination therapy.
3) Topical Antibiotics
Erythromycin and clindamycin - the most commonly used; also been used in combination with benzoyl peroxide.
The development of resistance is less likely in patients who are treated with a combination of benzoyl peroxide/erythromycin or clindamycin
MOA – Bacteriostatic to P. acnes; anti-inflammatory by suppressing PMNL
Indications – inflammatory lesions of mild to moderate acne
a. Clindamycin – as phosphate and hydrochloride in concentration of 1% as gel, lotion, foam, pledget, or solution; also available in combination with adapalene or BPO.
b. Erythromycin – in 2-3% as gel, solution, pledget or oitment; can cause burning, peeling, dryness and erythema.
c. Nadifloxacin – 1% cream inhibits enzyme DNA gyrase of P.acnes involved in DNA synthesis and replication.
Azelaic Acid - available by prescription in cream or gel of 10 – 20%. Transient burning can occur. It is safe in pregnancy.
Salicylic acid - it is a common ingredient of over-the-counter products in concentrations 0.5% to 10%; most commonly used as 2% wash and clenaser; lipid soluble ?-hydroxy acid has comedolytic properties; also causes exfoliation of the stratum corneum though decreased cohesion of the keratinocytes
1) Antibacterial Agents
Tetracyclines (doxy-, mino-, tetra-, and lymecycline) – preferred choice, on the basis of efficacy, safety and bacterial resistance
Others – macrolides ( azithromycin and erythromycin) and sulfamethoxazole (SMX) + trimethoprim (TMP)
Mechanism of action –
Antibacterial – bacteriostatic action on P. acnes by interfering with protein synthesis
Anti-inflammatory – by decreasing concentrations of FFAs, inhibiting macrophage action such as PMNL, chemo taxis, production of cytokine (IL-6 and TNF) and inhibiting inflammatory granuloma formation
Immunomodulatory actions – modulating host response
Indications – in moderate to severe acne and generally well tolerated; takes about 4 – 8 weeks to show clinical improvement
The dose can gradually be tapered or the drug can be withdrawn once the inflammatory acne have decreased or stopped appearing while maintaining remission with topical retinoids
Minimum duration of therapy – 6 – 8 weeks and maximum of 12 – 16 weeks
2) Oral Retinoids
The use of the oral retinoid, isotretinoin, has revolutionized the management of treatment-resistant acne
Targets all pathophysiologic factors in acne with direct action on reduction of sebum secretion by reducing the size (up to 90%), by normalizing follicular keratinization, by anti-inflammatory action and indirect action by decreasing P. acnes population by changing the follicular milieu
It also blocks skin androgen receptors in acne patients
Indications of Isotretinoin
Severe nodulocystic acne lesions
Severe acne variants like Gram – negative folliculitis, acne fulminans, and pyoderma faciale
Failure of conventional therapy
Moderate to severe acne relapsing frequently
Acne with severe psychological distress
Inflammatory acne with scarring
Approved dose – 0.5 – 2.0 mg/kg/day and drug is given over a 20 week course until a cumulative dose of 120 – 150 mg/kg body weight is achieved; therapeutic effects may take 1 -3 months to be visible.
3) Hormonal Therapy
The goal of hormonal therapy is to counteract the effects of androgens on the sebaceous gland.
This can be accomplished with the antiandrogens, or agents designed to decrease the endogenous production of androgens by the ovary or adrenal gland, including oral contraceptives, glucocorticoids, or gonadotropin-releasing hormone (GnRH) agonists.
Indications for Hormonal Therapy :
Patients with signs of peripheral hyperandrogenism like SAHA syndrome.
Patients with late onset acne (acne tarda) or persistent acne.
Patients with proven ovarian or adrenal hyperandrogenism.
Sometimes as an alternate to repeated courses of isotretinoin.
Acne resistant to conventional therapies.
Prominence of xacne on lower face and neck.
3 OCP – currently FDA approved for the treatment of acne: (1) Ortho Tri-Cyclen, (2) Estrostep, and (3) Yaz.
In an effort to reduce the estrogenic side effects of oral contraceptives, preparations with lower doses of estrogen (20 ?g) - for the treatment of acne.
Comedo Removal – useful for removing comedones resistant to other therapies and helps to improve the patient’s appearance .
Chemical Peeling –with 10-70% glycolic acid, Jessner’s solution and 10-30% salicylic acid; repeated peeling for acne scars and cystic lesions.
Cryotherapy - Used for acne and scars – cause erythema and desquamation of the skin.
Solid carbon dioxide is mixed with acetone to form a slush, which is brushed lightly over the skin.
Liquid nitrogen and cryo-spray can also be used.
For nodulocystic acne – refrigerant is directly applied on the skin.
Ultraviolet (UV) light - beneficial in the treatment of acne; The sunlight has a biologic effect on the pilosebaceous unit and P. acnes.
UVB can also kill P. acnes in vitro; UV radiation has antiinflammatory effects by inhibiting cytokine action.
Twice-weekly phototherapy sessions are needed for any clinical improvement.
Red light - penetrates deeper into the dermis; has greater anti-inflammatory properties à the combination of blue and red light may prove the most beneficial.
Treatments - be given twice weekly for 15-minute sessions for the face alone, and 45 minutes for the face, chest, and back.
Photodynamic Therapy - The topical application of aminolevulinic acid (ALA) 1 hour prior to exposure to a low-power light source (include the pulsed dye laser, intense pulsed light, or a broadband red light source)
The pulsed KTP laser (532 nm) - a 35.9?crease in acne lesions when used twice weekly for 2 weeks; lower sebum production even at 1 month
The pulsed dye laser (585 nm) - used at lower fluences to treat acne. Instead of ablating blood vessels and causing purpura, a lower fluence can stimulate procollagen production by heating dermal perivascular tissue. The beneficial effects of a single treatment can last 12 weeks.
Some of the nonablative infrared lasers, such as the 1,450 nm and 1,320 nm laser - helpful in improving acne; work by causing thermal damage to the sebaceous glands; 1,320 nm Nd:Yag and the 1,540 erbium glass lasers - improve acne.
-Removal of closed comedones – requires prior opening of their orifice with a small bore needle
-Cysts – require incision
-Atrophic acne scars - surgical management
Punch excision – up to subcutaneous level is mainly used for ice pick scars.
Elliptical excision is used for scar which require a punch larger than 3.5mm.
Skin grafting – in case of sinus tract or de-roofing a wide-based lesion.
Punch elevation – treatment of choice for depressed boxcar scar.
Subcision – treatment of choice for rolling or depressed scars. It works by breaking the fibrous strands that bind the papillary dermis to the deeper tissues, creating a controlled trauma leading to wound healing.
Chemical peels – superficial, medium and deep peels.
Microdermabrasion – mostly used for superficial scars. Can be performed with either aluminum oxide crystals or diamond tipped abrasive devices.
Percutaneous Collagen induction by microneedling – stimulates neocollagenesis and angiogenesis
Dermabrasion – works best for superficial scars; postoperative hypo- or hyperpigmentation may occur.
Combination therapy – using subcision, microneedling, & 15% TCA peel performed alternately at 2 week interval.
Tissue augmentation – Xenografts, autografts and homografts can be used. Injections of highly purified bovine dermal collagen have been used to correct defects caused by scars; Recollagenation.
Lasers and light therapy