Seeing your skin break out while you are unwell with an illness like a cold or the flu is a common experience. This skin reaction is not a coincidence, but a direct symptom of your body’s systemic response to fighting off an infection. The immune system initiates a cascade of physiological changes that affect your skin’s health and balance. Understanding this connection requires looking at the hormonal and inflammatory processes taking place inside your body.
The Link Between Stress Hormones and Inflammation
When you are sick, your body registers the infection as a form of physiological stress, which immediately activates the hypothalamic-pituitary-adrenal (HPA) axis. This activation triggers the release of stress hormones, most notably cortisol, from the adrenal glands. Elevated cortisol levels are a primary driver of breakouts during illness because they directly influence the skin’s oil production.
Cortisol promotes the activity of the sebaceous glands, leading to an increase in the production of sebum, the natural oil on your skin. This excessive oil production creates a more favorable environment for Cutibacterium acnes, the bacteria associated with acne, to thrive and multiply. The combination of more oil and more bacteria increases the likelihood of clogged pores, which are the initial stage of a pimple.
Simultaneously, the immune system’s fight against the illness generates widespread systemic inflammation. This protective response involves the release of pro-inflammatory molecules called cytokines. These inflammatory signals circulating in the bloodstream exacerbate existing acne lesions and can trigger new ones by causing local inflammation within the hair follicle. Systemic inflammation can also cause the oil within your pores to oxidize, which promotes acne formation and leads to redness and swelling.
How Sickness Changes Your Daily Habits
While the physiological response is the root cause, behavioral changes when you are unwell also contribute significantly to skin flare-ups. Illness symptoms like high temperature, vomiting, or diarrhea can rapidly lead to dehydration, which impairs the skin’s barrier function. When the skin barrier is compromised, it becomes more susceptible to irritation and less capable of healing, which can worsen breakouts.
Poor sleep quality and quantity, a common side effect of illness, further elevates stress hormone levels like cortisol, which then drives more oil production and inflammation. During the illness, many people also unintentionally neglect their regular hygiene, skipping face washing or failing to change pillowcases as often. This reduction in basic care allows dirt, oil, and bacteria to build up on the skin’s surface, leading to a greater number of clogged pores.
Constantly touching the face—such as wiping a runny nose or resting a feverish head on a hand—can transfer pathogens and bacteria onto the facial skin. Changes in diet, often involving simple carbohydrates or comfort foods that spike blood sugar, may also contribute to the inflammatory environment that promotes acne.
Treating and Preventing Breakouts When You Are Sick
Addressing illness-related breakouts requires a gentle and consistent approach that supports both skin health and overall recovery. Maintaining adequate hydration is arguably the most important step for both your illness and your skin, so focus on drinking plenty of water, broths, and electrolyte-containing fluids. This helps support the skin barrier, allowing it to better retain moisture and repair itself.
When it comes to skin care, the goal is to be gentle and avoid irritating an already stressed complexion. Use a mild, non-comedogenic cleanser twice a day with lukewarm water to remove excess oil and debris without stripping the skin’s natural moisture. If you choose to use an active ingredient, select a gentle acne treatment like a low-concentration benzoyl peroxide (2.5% to 5%) to target acne-causing bacteria, or salicylic acid to help unclog pores.
Apply these active treatments sparingly and only as spot treatments to minimize dryness and irritation. Changing your pillowcase daily, especially if you are sweating, reduces the transfer of bacteria and oil onto your face. If a breakout involves large, painful nodules or cysts that do not respond to gentle care, or if the rash appears unusual or spreads rapidly, consult a healthcare provider to rule out a secondary infection or other serious skin condition.