Sulphur, a solution for acne-prone skin?

Acne is a complex skin issue, influenced by factors such as hormones, genetics, and lifestyle. It is the most commonly encountered condition in outpatient clinical practice, accounting for approximately 9% of dermatologist consultations in France in 2022. In comparison, eczematous dermatoses, psoriasis, and skin cancer represented 3.7%, 3.5%, and 0.2% of consultations respectively.

From non-inflamed comedones to inflamed papules, pustules, cysts and nodules... there are several reasons why spots can develop, and they often combine.

• One of these reasons is the presence of bacteria responsible for acne. Although there are many strains of bacteria responsible for acne (Staphylococcus epidermidis and Staphylococcus aureus), the most common is Cutibacterium acnes (formerly Propionibacterium acnes). These bacteria naturally form part of the skin microbiota, but touching your face can introduce more of these bacteria than usual. They then penetrate the pores and their multiplication causes inflammation (redness, swelling, pus). It is this irritation that can give spots a red and irritable appearance.

• Theexcess of sebumis the primary cause leading to the emergence of skin imperfections. The hyperactivity of the sebaceous glands is a characteristic of oily skin, which can lead to several problems. Firstly, the accumulation of sebum in the pores can mix with other impurities and create hard "plugs" that further irritate the pore. These "plugs" are the origin of whiteheads and blackheads. Secondly, the bacteria responsible for acne feed on sebum. Therefore, the more sebum there is on the skin or in the pores, the more these bacteria can feed and multiply. Excess sebum can significantly contribute to the appearance of skin eruptions.

• Theaccumulation of dead skin cells is one of the potential factors that could be causing your spots. Your skin is constantly shedding dead cells and replacing them with new ones during the process of cellular renewal. Typically, young skin completely renews itself every 28 days. Most of these dead cells naturally flake off, but some remain and accumulate on the skin's surface. They can also penetrate the pores and contribute to the formation of hard "plugs" that cause whiteheads and blackheads.

It has been reported that sulphur is more effective against mild to moderate inflammatory acne and comedonal acne. Therefore, if you have red spots, blackheads, whiteheads or a combination of the three, sulphur can improve the appearance of your skin due to the numerous benefits it can provide. However, it is less effective in cases of moderate to severe forms of acne or cystic outbreaks, particularly when used as a standalone treatment.

• Absorbs Sebum: Sulphur aids in the absorption of excess sebum, a cause of acne, by drying out blemishes and freeing up clogged pores.

• Neutralises bacteria: When applied to the skin, sulphur is transformed into hydrogen sulphide (H2S) through the action of three enzymes present in the skin (cystathionine-γ-lyase, cystathionine-β-synthase and 3-mercaptopyruvate sulfurtransferase). This compound has a lethal effect on bacteria, including Propionibacterium acnes, thus preventing the spread of bacteria responsible for acne and causing irritations. Research also shows that sulphur is an effective treatment option for controlling vulgar acne caused by the bacterium Staphylococcus. It also kills fungi and other parasites.

• Exfoliates the skin: It has been demonstrated that sulphur has keratolytic effects, which means it aids the skin in shedding dead cells, thereby enhancing the renewal of skin cells. This property thus helps to prevent the clogging of pores (the precursor to a breakout) from developing.

• Alleviates inflammatory responses: Studies have shown that sulphur affects the permeability of the cellular membrane in tissue affected by pain. The action of this mineral enhances the effects of the body's pain-relieving hormones to reduce inflammation.

Whether you use it as a facial mask once or twice a week as a preventive measure, or as a targeted treatment to soothe stubborn spots, sulphur appears to be a quadruple threat to acne. Several clinical studies demonstrate its effectiveness on mild to moderate acne, with a significant reduction in the number of inflammatory lesions and comedonal lesions, with an improvement generally observed after 4 to 6 weeks of daily use.

However, the evidence is insufficient regarding its sole effectiveness on acne. Although sulphur-based treatments could potentially be useful on their own, sulphur is often combined with other topical agents, such as benzoyl peroxide, thesalicylic acid, sodium sulfacetamide or alpha-hydroxy acids (AHA) which have the same anti-inflammatory and anti-keratolytic properties as sulphur. Combined, they have a synergistic effect to enhance their effectiveness in treating acne. Therefore, further studies are needed to evaluate the effectiveness of sulphur for this use.

Sulphur against acne scars?

Sulphur is not a treatment for acne scars. There are more effective options available to promote wound healing and reduce the post-inflammatory hyperpigmentation, or professional treatments such as microdermabrasion and dermal fillers. That being said, sulphur can bring about certain improvements to the skin due to its exfoliating effects to even out the skin and lighten the brown spots, which may remain once an inflamed lesion heals.

• CRAIG G. E. & al. Benzoyl peroxide and sulfur: foundation for acne management. Canadian Medical Association Journal (1966).

• KLIGMAN A. M. & al. Is sulphur helpful or harmful in acne vulgaris? British Journal of Dermatology (1972).

• CARTER D. & al. Sulfur revisited. Journal of the American Academy of Dermatology (1988).

• NICOL K. & al. The use of sulfur in dermatology. Journal of Drugs in Dermatology (2004).

• DEL ROSSO J. Q. The use of sodium sulfacetamide 10%-sulfur 5% emollient foam in the treatment of acne vulgaris. Journal of Clinical and Aesthetic Dermatology (2009).

• BROWN J. N. & al. Treatment of Demodex-associated inflammatory skin conditions: A systematic review. Dermatologic Therapy (2019).