Acne vulgaris is a common
skin disorder characterized by non-inflammatory and inflammatory lesions
on the face and the upper trunks of the patient. It affects about 70%-80%
of adolescents and young adults. Patients with mild to moderate comedonal
or papulopostular acne can use topical therapy as a treatment. B-hydroxilacid
Salicylic acid (1-5%) can be used to treat comedonal acne in addition to
topical retinoid therapy.
What is Salicylic Acid?
Salicylic acid is a component in various over-the-counter products
that includes lotions, creams, alcohols-based solutions, and medicated
pads and it is more preferred among traditional peeling agents.
This acid is a derivative of benzoic acid that represents a carboxy-acid
attached to an aromatic alcohol phenol and this acid is contained
in a hydroethanol formula at 20-30% concentration. Salicylic encourages
the sloughing of dead skin like keratolytic agent. It is mild,
safe, and effective treatment for mild acne, oily skin, textural
changes and post inflammatory hyper pigmentation. It also works
on people with darker skin.
How does Salicylic Acid work?
Salicylic acid has strong comedolytic effects. It functions by
dissolving the intercellular cement that binds the epithelial
cells together and reduces the corneocyte adhesion. It is also
an excellent keratolytic agent that exhibits some degree of percutaneous
absorption and has lipophilic character facilitating the peeling
of the top layer of the skin and the opening of plugged follicles,
leading to the renewal of skin cell replacement cycle.
These comedones form when keratinization in the mid-section of
the follicular canal becomes too excessive. Salicylic acid, being
a lipophilic agent, goes into the middle of the sebaceous unit
to prevent the formation of comedones. It also affects the arachidonic
acid cascade and has anti-inflammatory properties useful in reducing
non-inflammatory as well as inflammatory acne lesions. Salicylic
acid can help unclog pores to resolve and prevent lesions, but
it can do nothing about the secretion of sebum form the sebaceous
gland nor does it have any effect on P. acne bacteria.
If treatment with salicylic acid is interrupted, the acne lesions
that have been healed may become clogged again, resulting in the
renewal of acne formation.
How Salicylic acid should be used?
The time period for application of salicylic acid is in proportion
to the dose absorbed because the skin efficiently absorbs salicylic
acids compared to other topical drugs. The efficiency of the absorption
of the salicylic acid in the skin is dependent on the duration
of skin contact and the medium of application. Some salicylic
acid ointment absorbs up to 20%-25% with a few minutes of skin
contact to reduce absorption (most topical drugs are left in contact
with the skin for up to 12 hours). Those preparations that contain
0.5% to 10% of salicylic acid are recommended for acne treatment.
In the US, up to 2% concentration of salicylic acid is permitted.
Salicylic acid can also be used in children.
If salicylic acid is applied to a large surface area of the skin
for a long time, salicylate toxicity may occur, even this is rare
with topical applications. Taking salicylic acid orally may lead
to excessive stomach irritation.
Side effects associated with Salicylic acid usage
There may be skin exfoliations and discomfort on salicylic concentrations
more than 2%. The adverse reactions appear when there is a systemic
use or a prolonged exposure of the skin area (toxic inner ear
damage and hypersensitivity) though common side effects involve
only the skin dryness. When symptoms like heavy breathing, dizziness,
hearing impairment, lethargy, digestive disorders, and nausea
persist, patients should consult their doctors. Pregnant women
should first consult their doctors before treating acne with salicylic
acid since this medicine can be absorbed through the skin. Salicylic
acid is an FDA Pregnancy category C drug.
Salicylic acid therapy is proven to significantly reduce acne
severity as reports of moderate to good improvements have been
documented. Salicylic acid can be used with traditional acne therapy
to accelerate the resolution of the comedones and inflammatory
papules; its inflammatory character is also helpful for post inflammatory
erythma. Caution is to be observed while using the treatment because
of the rapid and efficient percutaneous absorption of the drug.