Acne, Purging, Irritation, and Gram-Negative Folliculitis

I’m about to say something that could upset skin communities everywhere: I don’t really believe in purging. Before you panic, let me explain.

When I was in my 20s, I went through a period of acne that the Internet affectionately called “purging.” I talked about it a bit in my post on how to pick and prepare for your first dermatologist visit. It was a very painful period in my life that I was urged to power on through.

Again and again, I see people asking about purging, telling others they’re purging, describing the breakouts from a new cleanser as purging, and even popular YouTubers suggesting that antioxidants like Vitamin C made them purge for six months. I want to dispel this myth right here and now: Your skin does not purge and the idea of purging is a far overemphasized everywhere. In one of Dr. Dray’s videos on YouTube, she mentioned this as well and described most people’s reactions as irritation.

As I dug into this topic over the past few weeks, I could find no medical evidence at all to support this idea of prolonged breakouts from AHAs or BHAs, or even tretinoin. Irritation is referenced several times – peeling, redness, and dryness – and indeed doctors will tell you that your skin may show some signs of worsening for a short period before it gets better, but there is nothing to support the idea of long-term breakouts from products. This term also gets tacked onto regular products, such as moisturizers and cleansers.

On top of this, I’ve seen people refer to acne breakouts from products (such as cleansers and moisturizers) as an allergic reaction, which I dig into a bit below.

So to tackle this, I want to talk a bit about how skin works, the mechanisms of acne, the type of reactions to products, and a common form of folliculitis that is frequently mistaken for worsening acne.

Please keep in mind that this post is not intended to diagnose you, but instead to debunk commonly held misconceptions and ideas. If you feel like you identify with one of the skin conditions or reactions detailed below, please speak to your doctor.

The Anatomy of Skin and the Pilosebaceous Unit

The skin is divided into three major layers: the epidermis, the dermis, and hypodermis. The epidermis contains the skin cells we see and frequently consider our skin, and is the layer affected by topical products and environmental conditions. It is broken into four distinct layers, with new corneocytes starting at the stratum basal (the layer right over the dermis), where they split into two thanks to the magic of mitosis, and one cell stays while another drifts towards the surface (the stratum corneum), becoming full of keratin, bonded by NMFs, and flattened down, before they eventually live out their lives being covered in moisturizers and exfoliants, and then sloughing away to cover our belongings in dust.

apocrine-sweat-glands-2The skin is also made up of many glands, such as the sebaceous glands (oil glands) and sweat glands (two types – apocrine and eccrine). Eccrine glands are most common on hands and feet, while apocrine glands are attached to the hair follicle, along with a sebaceous gland. This makes up the pilosebaceous unit. These are most common on the face, and is what becomes inflamed and plugged up when you have acne or folliculitis.

Fun fact: Sweating does not “clean” pores out either. The sweat glands are positioned too far up to actually “push out” the build-up that creates acne deeper in the unit. The scent of sweat is largely due to the sweat mingling with the microflora on the skin.

The body naturally produces a makeup of natural moisturizing factors (NMFs), which act as natural humectants, as well as a mixture of other fluids such as sebum. I talked about this with more detail in my post on dehydrated skin. This mixture creates what is known as the acid mantle. Together, it works to keep skin cells sloughing away, invaders out, and moisture in. Unfortunately, for a variety of factors, skin might not be the most effective at one of its natural processes (such as hormones pressing the gas on sebum production), so acne develops.

Acne, a condition characterized by hyper-keratinization, occurs when sebum, bacteria (p. acnes, which lives on everyone’s skin naturally), and corneocytes that didn’t slough away naturally, build up in the pilosebaceous unit. This creates a comedone.

Comedones begin as microcomedones (comedo- means acne or blockage), which later balloon to create an inflammatory lesion. As they get larger, and especially if squeezed, they can erupt the wall of the follicle, leaking the infection into the surrounding tissues.

This is all important because in the past, I (incorrectly) thought that acne occurred anywhere in the skin tissue and was not exclusive to a follicle. Hopefully, if you also used to think this, now you know!

How Acne Products Work

Without getting too into the weeds (future post!), acne products largely work by disrupting or killing the acne bacteria (such as benzoyl peroxide, which kills p. acnes through the release of free oxygen radicals), normalizing skin cell turnover, and by reducing inflammation in the skin. Not all acne topicals are anti-microbial, anti-bacterial, anti-inflammatory, or cell-communicators, but they all are used for combating one or several of the mechanisms of comedone formation.

According to the American Academy of Dermatology (Source):

Commonly used topical acne therapies include BP, salicylic acid, antibiotics, combination antibiotics with BP, retinoids, retinoid with BP, retinoid with antibiotic, azelaic acid, and sulfone agents.

The process of reversing the mechanisms of acne (or at least slowing them down) varies by medication, but anecdotally, it seems that the quicker the brakes are applied, the more irritating the process is. For example, tretinoin is perhaps one of the quickest medications to act on acne (Adapalene takes roughly 12 weeks, for example), while azelaic acid appears to be one of the slowest.

Adverse Reactions and Irritation

An adverse reaction can be described as any unwanted effect associated with a treatment. Sometimes this can lead to new discoveries, such as the discovery that a particular medication for glaucoma made patient’s eyelashes grow longer, but many times it is just aggravating.

Basic Skin Irritation

Simple skin irritation is what most people think of when they think of “irritation.” It is redness at the site of application (though people of color can frequently see a decrease in color in their skin rather than redness) and usually occurs within 6-24 hours, though people with very sensitive skin may see a reaction within just a few hours.

Short-term use of anti-inflammatories and corticosteroids usually resolves the issue and rarely do medical professionals need to get involved.

Cumulative Irritation

Cumulative irritation is like a slow-burn irritant. It’s the product you put on for a few days and then one day – boom! Your skin reacts with redness and tenderness, like basic irritation. This is the most common with many topical prescription acne treatments that can cause redness, dryness, and peeling.

There can be several factors that cause this, from other ingredients in a skin care regime not mixing well with each other to skin simply becoming more sensitized and reactionary as time goes by.

Discontinuing use of the product and returning to a bland routine (cleanse, moisturize, sunscreen) as well as anti-inflammatories usually resolves this issue as well. If it is a topical prescription, contact your doctor for instructions.

Allergic Reactions

Allergic reactions are defined by almost immediate hypersensitivity and can be severe, with swelling, redness, hives, or anaphylactic shock. If the individual is less allergic, it can take 24 hours or more to present with itching, swelling, and redness. Mild reactions can be treated with Benadryl, while more severe reactions should be treated by a medical professional.

The primary differentiation between allergic reactions and other reactions is that allergic reactions usually last longer, can spread, and cannot be re-introduced once the reaction has resolved.

Gram-Negative Folliculitis

While many modern acne treatment guidelines dissuade the use of oral or topical antibiotics (eg, erythromycin and clindamycin) due to growing antibiotic resistance (Source), many people are still prescribed these treatments in combination with topical retinoids. In it’s place has come azelaic acid (which does not produce p. acnes resistance) and benzoyl peroxide.


2016 AAD Guidelines for the Management of Acne Vulgaris (Source)

Besides antibiotic resistance, oral and topical antibiotics can also produce another unwanted side-effect: gram-negative folliculitis (p. acnes is gram-positive). According to Herbert P. Goodheart (Goodheart’s Photoguide to Common Skin Disorders: Diagnosis and Management), folliculitis, “in it’s broadest sense, may be defined as a superficial or deep infection or inflammation of the hair follicles.” This usually occurs when an irritant – either physical or chemical – is introduced to the skin that can aggravate the follicles.

Gram-negative folliculitis is an acne-like “rash” (referred to in some literature as a “pustular rash”) caused by bacteria. The term “gram-negative” simply refers to the staining pattern of the organisms. It usually appears in patients with acne and is often mistaken as worsening acne in those patients. It is also most commonly found around the mouth, under the nose, to the chin and cheeks.

While folliculitis is not limited to patients using antibiotics by any means (men frequently report folliculitis in their beard, for example, and pityrosporum folliculitis is a common form of fungal folliculitis typically found on the upper trunk of the body), gram-negative folliculitis specifically seems to most commonly appear in patients who are immunocompromised, have been on rounds of oral antibiotics recently, or given topical antibiotics like clindamycin. From the Journal of the American Academy of Dermatology:

This uncommon disorder presents as uniform and eruptive pustules, with rare nodules, in the perioral and perinasal regions, typically in the setting of prolonged tetracycline use. It is caused by various bacteria, such as Klebsiella and Serratia, and is unresponsive to many conventional acne treatments. Gram-negative folliculitis is typically diagnosed via culture of the lesions, and is generally treated with isotretinoin or an antibiotic to which the bacteria are sensitive. In cases of acne unresponsive to typical treatments—particularly with prominent truncal involvement or monomorphic appearance—pityrosporum folliculitis should be considered. Staphylococcus aureus cutaneous infections may appear similar to acne, and should be considered in the differential, particularly in cases of acute eruptions; a swab culture may be helpful in these cases.

According to William J Cunliffe (Acne: Diagnosis and Management, 2001), “Approximately 80% of patients with cases of Gram-negative folliculitis present with superficial pustules, while the remaining patients [20%] present with deep nodules and pustules. … The possibility of a Gram-negative folliculitis should be entertained if a patient develops a highly inflamed flare after doing well on antibiotics.”

Examples of antibacterial agents used to treat acne that gram-negative folliculitis bacteria are not sensitive to include:

  • Tetracyclines: doxycycline and minocycline
  • Macrolides: erythromycin and azithromycin
  • Clindamycin

It’s important to note that pityrosporum folliculitis is a separate disease – fungal in nature – and is not treated the same as acne or gram-negative folliculitis.

Anecdotally, this is the type of reaction I see the most when people start to viciously break out from a prescription acne product suddenly, along with skin redness and basic irritation. It usually comes on acutely – such as overnight or within 48 hours – is itchy, tender, and sore. Unfortunately, these characteristics sound a lot like acne to many people, especially those already suffering, and thusly, it is frequently mislabeled as “purging.”

Treatment Options

If you have experienced this kind of reaction, it is important to talk to your doctor about it, as they are the only ones that can truly help you – not the Internet. However, most cases are confirmed by sampling and culturing the lesions, and swab samples from the nose (where the causative bacteria lives) can be taken.

Doctors may advise you an antibiotic therapy, using antibiotics that the organisms are sensitive to (ampicillin and trimethoprim, specifically), though this treatment is not always successful. Isotretinoin, which suppresses sebum production in the pilosebaceous duct and dries out the mucous membranes (especially the nasal passages) is generally preferred (.5-1.0g/day) for 4 months.

Some Acne Guidelines

So in short, I don’t really believe in what is frequently considered purging. Yes, acne medications can frequently resolve comedones quicker, but they can also just as frequently cause irritations and other adverse reactions, particularly when used aggressively, which is often mistaken for other conditions.

With this in mind, here’s a few guidelines for products when treating your acne:

  • If you begin to break out from non-prescription products, it is just breaking out or irritation. Cleansers cannot “purge” acne, your moisturizer cannot “purge” acne, nor can your vitamin C “purge” acne. It is simply adverse reactions to the product (and an ingredient or combination of ingredients within) and your skin not getting along. Additionally, most OTC products (such as BHAs and AHAs) do not contain a high-enough percentage to worsen breakouts significantly but can irritate your skin.
  • If your acne becomes itchy or flares up immediately, as if overnight, call your dermatologist. This is especially important if you’ve been on oral antibiotics or using a product with topical antibiotics, including clindamycin combinations (ex.  Ziana or Veltin).
  • If your skin becomes tender, red, or burns upon contact with any products, such as cleansers or moisturizers, or even water, while on acne treatments, talk to your doctor. Your skin may be irritated and your prescription may be adjusted.
  • Gram-negative folliculitis is not fungal, it is bacterial. Unlike pityrosporum folliculitis, gram-negative folliculitis is not treated with fungal treatments.
  • Your skin may get worse for the first two or three weeks when using a prescription acne treatment. I feel like this period is where “purging” really got it’s name and is what it should be carefully confined to describing. If your breakouts last longer than this time period or get much worse, painful, or deep, particularly in locations around the cheeks, chin, and mouth, contact your doctor.


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