Acne vulgaris is a common skin disorder affecting about 70%-80%
of adolescents as well as young adults. It is characterized by
both non-inflammatory and inflammatory lesions on the face and
upper trunk of the patients. For most patients with mild to moderate
comedonal or papulopustular acne, topical therapy is the most
appropriate treatment option. Salicylic acid (1-5%) is a b-hydroxyacid
that can be used as a topical peeling agent to treat mild comedonal
acne in addition to topical retinoid therapy.
What is Salicylic Acid?
Salicylic acid is preferred to other commonly used traditional
peeling agents. It is a component in various over the counter
acne products including lotions, creams, alcohol based solutions
and medicated pads. Salicylic acid is contained in a hydroethanolic
formula at a 20%-30% concentration. This acid is a derivative
of benzoic acid and represents a carboxy acid attached to an aromatic
alcohol phenol. It is mild and works like a keratolytic agent
i.e. it encourages the sloughing of dead skin cells. It is a safe
and effective treatment for mild acne, oily skin, textural changes
and post inflammatory hyper pigmentation and in people with darker
How does Salicylic Acid work?
Salicylic acid is an excellent keratolytic agent exhibiting some
degree of percutaneous absorption and functions by dissolving
the intercellular cement that binds the epithelial cells together
leading to the reduction in the corneocyte adhesion. Salicylic
acid has a lipophilic character that facilitates the peeling of
the top layer of skin and the opening of plugged follicles, which
leads to a renewal of the skin cell replacement cycle. Thus, Salicylic
acid has a strong comedolytic effect.
Comedones are formed due to excessive keratinization in the mid
section of the follicular canal. A lipohhilic agent like salicylic
acid goes in the middle of the sebaceous unit and prevents the
formation of comedones. Salicylic acid affects the arachidonic
acid cascade and has anti inflammatory properties also. Hence,
it is useful in reducing both non-inflammatory as well as inflammatory
acne lesions. Salicylic acid helps unclog pores to resolve and
prevent lesions but cannot affect the secretion of sebum from
the sebaceous gland or have any effect on the P.acnes bacteria.
Salicylic acid must be used continuously even after the acne
lesions have been healed as a maintenance therapy, because if
application is stopped the pores become clogged once again and
there is renewal of acne formation.
How Salicylic acid should be used?
Absorption of salicylic acid in the skin is more efficient compared
to other topical drugs. The time period for application of salicylic
acid should be in proportion to the dose absorbed. How efficiently
the absorbed salicylic acid works depends on the duration of skin
contact and the medium of application. It has been seen that some
salicylic acid ointment led to a 20%-25% of absorption. While
most of the topical drugs are left on the skin surface for 8-12
hours, preparations containing salicylic acid should be taken
off after a few minutes so as to reduce the amount of absorption.
Preparations which have a concentration of .05%-10% of salicylic
acid are recommended for use in acne treatment. However, in all
non-prescription acne preparations, the concentration up to 2%
of salicylic acid is permitted in the U.S. Salicylic acid can
be used in case of children also.
It should be kept in mind that though systemic toxicity is a
rarity with topical application, if the drug is applied to a large
surface area of the skin for a long time, there may be occurrence
of salicylate toxicity.
Salicylic acid is not to be taken orally as it leads to excessive
Side effects associated with Salicylic acid usage
In all preparations where the concentration of salicylic acid
is more than 2% there may be exfoliation of skin and discomfort.
The most common side effect is dryness of skin which is usually
mild. Adverse reactions are experienced when there is systemic
use or if it is used over a large area for long. These reactions
are toxic inner ear damage and hypersensitivity. Also patients
using salicylic acid preparations should consult their doctor
when the experience side effects like heavy breathing, dizziness,
hearing impairment, lethargy, digestive disorders, and nausea.
Salicylic acid is n FDA Pregnancy Category C drug so women who
are pregnant should consult their doctors as this medicine can
be absorbed through the skin.
Salicylic acid has been proven to significantly reduce acne severity
and most patients report moderate to good improvement with this
therapy. Salicylic acid peels can be used alongside traditional
acne therapy to speed up resolution of the comedones and inflammatory
papules. And its anti inflammatory character is also helpful for
post inflammatory erythema. However, due to rapid and efficient
percutaneous absorption of the drug, it is wise to take a cautious
approach while using this drug.