Acne
02 September 2022
If you have facial acne, there’s a good chance that you might be suffering from back acne or truncal acne. Actress and dancer, Maddie Ziegler has opened up about her struggle with back and body acne for the last 2 years. More recently, K-pop band member, Hong Eunchae of girl group LE SERRAFIM, faced public criticism when her back acne was seen during a public performance. Back acne (or “bacne”) affects 48-52% of patients with facial acne; and its effects on a person’s self confidence, especially when it comes to wearing clothes that reveal the back, neck and chest that expose acne on these areas.
Back acne has been associated with people who work out. However, back acne can also affect people who do not exercise frequently. The underlying pathophysiology of back acne is similar to acne of the face; with some difference due to the nature of the skin of the back. Here’s your doctor’s guide to back acne and how to get it treated.
Back acne refers to acne of the back, including the upper back and shoulders. Truncal acne can occur in adolescence and adults; and has a slight male predominance.
Back acne can range from:
• Closed comedones
• Open comedones
• Papules
• Pustules
• Cysts and nodules
These lesions tend to be clustered near the center of the back. More severe cases of back or truncal acne, acne conglobata, is seen as nodules and abscesses on the back. Not to be confused with back acne, which has bacterial origins, “fungal acne” is actually malassezia folliculitis that is not acne. This topic has been covered in depth in this blogpost, Fungal Acne is NOT Acne At All.
Back acne is caused by a combination of factors that result in clogged pores and inflammation. It is essentially, a disease of the pilosebaceous units in the skin of the back or trunk. Although often referred to as “oil glands”, pilosebaceous units consist of the sebaceous gland (the oil gland), hair follicle and a small muscle that causes the hair follicle to stand on its end (arrector pili muscle). The opening of the pilosebaceous unit is what we see as a pore.
A combination of four key steps in the skin lead to back and truncal acne. Increased sebum secretion of the oil glands and the increased stickiness of the cells lining the follicle causes the pores to become clogged. These clogged pores create an environment for bacterial colonisation by C.acnes. Subsequently, inflammation occurs.
Although there are differences between the skin of the face and the trunk in thickness, pH and distribution of the sebaceous glands, the pathogenesis of back and truncal acne is the same as facial acne. However, truncal skin is more vulnerable to occlusion from sweat and oils; and mechanical stimuli such as friction and pressure. If you exercise frequently or wear tight clothing; read on to find out what you need to know.
Sweating can be a precursor to back and truncal acne. When left on the skin for a prolonged period of time, sweat mixed with dirt and oils can clog pores, especially in people who are already acne-prone. Acne mechanica is a specific type of acne caused by the mechanical stresses of friction, pressure and compression. This type of acne can be seen in people who wear tight, restrictive clothing or equipment (e.g. helmets). These compressive forces cause acneiform eruptions on the back and trunk, similar to maskne due to mask wearing.
Acne mechanica on the trunk can occur where the clothing compresses on the skin such as the area along the sports bra.
Related blogposts:
Maskne: How to Avoid Acne from Wearing Surgical Face Masks
Skincare & Makeup Tips for Wearing Face Masks
Other factors that can also contribute to back and facial acne are:
Hormones
Our body has natural circulating hormones; which affect the biological functions of the sebaceous glands. Hormones such as testosterone and cortisol induce hyperseborrhea of the sebaceous glands. In response to the rise in androgen levels during puberty, acne on the face and body can develop.
Endocrine abnormalities are also associated with acne. Patients with conditions such as polycystic ovarian syndrome and Cushing’s syndrome frequently report of acne in their face and trunk.
Medications
Medications such as steroids and anti-convulsants can cause acne.
Stress
During periods of emotional and pyschological stress, our bodies release stress hormones which increase sebum production. This increase in oiliness contributes to acne.
Diet
The role of diet and acne has been covered in detail in this blogpost Acne & Diet: Foods to Avoid for Less Pimples.
Back acne is associated with post inflammatory hyperpigmentation and scarring- both hypertrophic and atrophic scars (depressed scars).
Steps you can take to avoid back acne are centered around back hygiene to prevent the accumulation of sweat, oil and dirt on the skin. Essentially, keeping your back clean and dry is important to manage pimples.
Here’s your guide to staying fit without acne:
• Switching to loose fitting clothing helps to reduce the friction and compression of acne mechanica from tight fitting clothing.
• Avoid the accumulation of sweat and dirt on your skin by showering as soon as you can after a workout; and change into clean and dry clothing.
• If you are unable to shower immediately after a workout, wipe away sweat with a clean towel and change in to clean, dry loose clothing.
• Wear clean clothing when you exercise
• Switch your hair products if they are rich in oils. Hair products, especially those rich in oils, can transfer to the back and also clog pores.
Over-the-counter active ingredients that you can start with at the drug store, without a doctor’s prescription:
Related blogpost:
5 Skincare Ingredients for Acne & Acne Prone Skin
Benzoyl peroxide for back acne
One of the most widely used active ingredient for acne is benzoyl peroxide. Benzoyl peroxide has anti-bacterial effects against C.acnes. It also reduces the inflammatory lesions in acne. Benzoyl peroxide can be found in wash-off cleansers and leave on creams. If you’re choosing a wash off cleanser that contains benzoyl peroxide, remember to leave it on your back for 2 minutes at least; to allow for sufficient penetration and deposition of benzoyl peroxide on the back.
For benzoyl peroxide as leave on gels or creams, you can start with a concentration of 2.5%. Benzoyl peroxide is known to bleach clothing and bed linens- so to avoid this, ensure that your back is dry after applying benzoyl peroxide before wearing your clothes or lying down.
Salicylic acid for back acne
Another effective active ingredient for back acne is salicylic acid. Salicylic acid exfoliates the skin to remove the top layer of dead skin on the surface. This acid is oil soluble, so it can penetrate deep into the pores to unclog the pores of excess oil and dirt. The exfoliation benefits of salicylic acid also help to reduce post-inflammatory hyperpigmentation caused by acne. To learn more about the different types of acids in skincare, please see A Complete Guide to Acids in Skincare & Chemical Exfoliation.
If you find that your back acne is still persistent despite your best efforts, it might be time to seek your doctor’s help. Treating back acne is more challenging than acne of the face because the skin of the back is thicker. Acne on the back can also be harder to reach for application of topical medications.
Similar to acne on the face, persistent and severe cases of back acne will benefit from a doctor’s evaluation. Some of the medications that may be prescribed by your doctor include these medications. The recommendations will depend on the specifics of the patient’s acne.
• Retinoids
Retinoids reduce sebum secretion by the oil gland, unclog pores and reduce the size of the oil glands. Using retinoids also helps to reduce scarring caused by back acne. Depending on the severity of acne, retinoids can be prescribed for topical application (retinoic acid), or in more severe cases, in the oral form (isotretinoin)
Related blogposts:
The Beginner’s Guide to Retinoids
5 Affordable & Popular Retinoid Serums Reviewed
Is Isotretinoin (Roaccutane) Dangerous?
• Azelaic acid
Azelaic acid has antibacterial benefits against C. acnes, the bacterial culprit behind acne. It also reduces the inflammatory component of acne, helping to calm down angry, red pimples.
Related blogpost:
Azelaic Acid: A Multi-Tasking Skincare Active to Know
• Antibiotics
Antibiotics can reduce the bacterial load in acne. Some of these antibiotics may also reduce inflammation on the skin, and in turn, reduce the likelihood scarring due to acne
• Hormonal therapy
Spironolactone is originally a blood pressure medication that was found to have anti-acne benefits in patients with hormonal acne. This medication blocks androgen receptors, thereby reducing the effect of androgen increasing sebum production on the skin. In general, truncal acne tends to have a slower response than facial acne. Hence, back acne, especially for severe cases, will require a multidisciplinary treatment strategy.
Some of the in-clinic treatment procedures for back acne include chemical peels, Q-switched lasers and intralesional steroids. You can read more about these treatments in detail in these blogposts:
10 Things to Know Before Having Lasers
The Truth About Chemical Peels
Acne Steroid Injections & When Popping a Pimple Could Kill You
Treating back acne is more challenging than facial acne. Factors like choice of clothing and hygiene can contribute to back and truncal acne. If you do not see an improvement in your back acne after 6-8 weeks, consider seeing your doctor to understand your treatment options for better outcomes.
References:
1. Gaps and recommendations for clinical management of truncal acne from the Personalising Acne: Consensus of Experts panel. Tan et al.JAAD Int.2021 Aug 17;5:33-40.
2. Truncal Acne: An Overview. Woo and Kim. J Clin Med. 2022 Jun 24;11(13):3660.
3. A review of diagnosis and treatment of acne in adult female patients. Tan et al. Int J Womens Dermatol. 2018 Jun; 4(2): 56–71.
