Salicylic acid is a type of beta hydroxy acid that is derived from willow bark and works as a keratolytic agent. In addition to being an effective treatment for acne, salicylic acid can also be used to treat other skin conditions such as psoriasis, seborrheic dermatitis, and dandruff.
Salicylic acid does not have any effect on Malassezia but is a good topical treatment that can help reduce flaking and scaling in seborrheic dermatitis. However, it also has the potential to cause more irritation. Use a gentle formulation, and only in the scaling phase.
Let’s take a deep dive:
What is salicylic acid?
Salicylic acid (SA) has been used topically to treat all sorts of skin disorders for more than 2000 years. This compound is mostly derived from willow bark but other natural sources include sweet birch and wintergreen leaves. SA can also be synthesized artificially.
SA is not actually a beta-hydroxy acid but a phenolic aromatic acid. It’s thought that SA was labelled a beta-hydroxy acid when it was introduced to the market as it was easier for the general public to identify with. But really, what kind of acid it is doesn’t matter to us plebs, we just want to know whether it works.
How does salicylic acid work?
Salicylic acid is a keratolytic ingredient that works by exfoliating the stratum corneum (the outermost layer of the skin). SA breaks down the bonds between dead skin cells. This process allows new skin cells to form and pushes out impurities, making way for fresh, smooth skin.
Not only does salicylic acid promote cell turnover, but it also has anti-inflammatory and antimicrobial properties. This makes it an ideal ingredient for treating acne, as it can help to reduce redness and swelling while fighting off bacteria.
Is salicylic acid antifungal?
There is some evidence that salicylic acid may be effective against some types of fungi, although the evidence is limited. A lab study showed that SA could kill Eutypa lata (a type of plant fungus) at higher concentrations.
Another lab study showed that salicylic acid can enhance the activity of common antifungal drugs against Candida and Cryptococcus. At time of review, there were no published studies looking at salicylic acid’s activity against Malassezia.
Which makes us question, why do we so often use salicylic acid for seborrheic dermatitis?
Is salicylic acid good for seborrheic dermatitis?
Salicylic acid is oil-soluble, which means it can penetrate the skin deeper than alpha-hydroxy acids. SA is extremely helpful for SD sufferers with large pores and acne-prone skin. The compound penetrates into the pores, dissolving excess sebum and debris.
A small study combined intense pulsed light (IPL) and 30% supramolecular salicylic acid and found that the combination is effective at treating seborrheic dermatitis.
SA is also said to have an anti-inflammatory effect and can help reduce skin redness. However, it is by no means soothing.
Salicylic acid can leave you with dry skin and cause more irritation if you are having a seborrheic dermatitis flare. SA can also leave you with temporary skin redness.
If you suffer from seborrheic dermatitis, your skin barrier is already affected. Don’t use SA while your skin is inflammed. You can try applying salicylic acid during the flaking phase to reduce scaling. However, use a a mild formulation (less than 2%), and cease immediately if it irritates.
The scalp is a different kettle of fish. I prefer salicylic acid shampoos to ketoconazole or zinc pyrithione shampoos for dandruff and scalp seborrheic dermatitis.
In fact, a small study showed that shampoos containing ciclopirox olamine and 3% salicylic acid (CPO/SA) improved seborrheic dermatitis and dandruff as much as ketoconazole 2% shampoo. Plus, only subjects using the CPO/SA shampoo reported a significant reduction in itching. And we all know how annoying an itchy scalp is.
Benefits of salicylic acid for the scalp
Salicylic acid is a popular ingredient in anti-dandruff shampoos. SA works by softening the scalp and exfoliating the excess dead skin. This allows a new layer of cells to form more quickly. SA can also reduce oil on the scalp breaks down sebum build-up.
Salicylic acid is commonly recommended for proriasis of the scalp. This is because SA is keratinolytic and can soften psoriatic plaques, allowing other topical treatments to be absorbed better.
The compound is also used in hair loss prevention shampoos. Whether or not SA is a good treatment for hair loss remains to be proven.
Benefits of salicylic acid for the face
Salicylic Acid is popular over-the-counter topical agent that is recommended to treat a variety of skin conditions including acne, seborrheic dermatitis, hyperpigmentation, age spots and scars.
The compound penetrates the skin, dissolving debris in clogged pores and exfoliating dead skin. Salicylic acid also reduces inflammation and redness and can help cystic inflammed acne heal quicker.
OTC salicylic acid skincare products are a great DIY home option for those who want to maintain clear complexion without resorting to harsh abrasive peels or surgery.
Just make sure you don’t overdo it.
Precautions when using topical salicylic acid preparations
As much as some brands like to market that their salicylic acid formulation is gentler than others, all salicylic acid can irritate the skin, causing burning and redness. This is especially so when you have sensitive skin or if you use it too often.
If you already have dry or sensitive skin, avoid using SA, or at least use it sparingly. If you are in the inflammed phase of seborrheic dermatitis, i.e the red, itchy, burning phase, totally avoid SA. It will sting like crazy and break down your already broken-down skin barrier.
You shouldn’t use salicylic acid when you’re pregnant. If you’re breastfeeding, the amount of salicylic acid in your breastmilk is negligible if you use it topically. However, make sure you don’t apply allow your baby to ingest it directly by applying it near to your nipples.
If you are allergic to aspirin, avoid SA.
To wrap up
Salicylic acid is a good topical treatment that can help reduce flaking and scaling in seborrheic dermatitis. However, it also has the potential to cause more irritation. Use a gentle formulation and try it on a small area first.