Eczema (Atopic Dermatitis) is a chronic inflammatory skin condition characterized by dry, itchy, and inflamed skin. This common disorder disrupts the skin’s natural protective barrier, making it vulnerable to external threats. Staphylococcus aureus is a bacterium commonly found on human skin and in the nose. While often harmless, the compromised skin of an eczema patient creates a significant risk for this bacteria to overgrow and cause an active infection. This complication is prevalent, with most individuals suffering from moderate-to-severe eczema experiencing colonization by this bacterium at some point.
How Eczema Breaks Down the Skin Barrier
The skin’s primary defense against pathogens is the stratum corneum. In many cases of eczema, genetic variations lead to a deficiency in the protein filaggrin, which is essential for assembling this barrier layer. This structural defect results in a weakened barrier that easily loses moisture and develops microscopic cracks. These fissures act as direct entry points, allowing bacteria like S. aureus to penetrate deeper skin layers.
Healthy skin maintains a diverse community of microorganisms (the skin microbiome) that helps defend against invaders. Eczematous skin, however, often exhibits a reduction in this microbial diversity (dysbiosis). This imbalance creates an opportunity for opportunistic bacteria to thrive, leading to a higher concentration of S. aureus on the surface.
S. aureus is particularly adept at colonizing compromised skin. Studies estimate that up to 90% of individuals with active Atopic Dermatitis are colonized, compared to only about 5% of healthy adults. This high bacterial load significantly increases the probability of an active infection. The bacteria can also release toxins that disrupt the skin barrier further, worsening inflammation and increasing the urge to scratch.
Chronic, intense itching (pruritus) is a hallmark of eczema that creates a self-perpetuating cycle of damage. Repeated scratching causes physical trauma, creating micro-abrations and open wounds on the skin surface. These self-inflicted wounds bypass the weakened natural barrier, providing a direct route for bacteria. These open lesions provide a rich environment of proteins and moisture that S. aureus utilizes for rapid replication.
Signs of a Secondary Staph Infection
A secondary staph infection often presents as a sudden and unexplained worsening of eczema, even when the patient is adhering to their regular treatment regimen. The rash may become rapidly more inflamed, irritated, and resistant to standard eczema therapies. A distinct visual sign of active infection, known as impetiginization, is the appearance of thick, golden, or honey-colored crusts on the skin surface.
These infections commonly cause the affected skin to weep or ooze a clear or pale-yellow fluid. This persistent moisture indicates a significant inflammatory response and severe compromise of the skin barrier. The affected area may also develop small, pus-filled bumps (pustules) or blisters that easily break open.
While eczema is typically itchy, a bacterial infection introduces new symptoms of localized pain and warmth. The infected areas will often feel noticeably hot to the touch. Redness may also deepen and become more defined around the borders of the rash, and in some cases, red streaks may appear to be spreading from the site.
In more severe or widespread cases, the infection may progress beyond the skin surface, requiring immediate medical attention. Systemic symptoms can include a fever (over 100.4° F), general malaise, or swollen lymph nodes near the infected area. Recognizing these signs quickly is important for preventing the infection from spreading further or evolving into a more serious condition like cellulitis.
Reducing the Risk of Infection
Proactive management is aimed at restoring the skin’s integrity to prevent bacterial entry.
Barrier Restoration
Regular and liberal application of emollients or moisturizers is the primary strategy for sealing the compromised barrier. Applying these immediately after bathing helps lock in water. This reduces the dryness and cracking that invites pathogens.
Hygiene and Decolonization
Proper bathing techniques are necessary to cleanse the skin without causing further irritation. Baths should be kept lukewarm and short, typically less than 10 minutes. Using a gentle, non-soap cleanser helps remove surface debris and bacteria. For frequent colonization, a healthcare provider may recommend a diluted bleach bath protocol. This involves adding a small amount of household bleach to the bathwater to reduce the bacterial load of S. aureus. This should only be used under medical guidance, usually two to three times a week.
Preventing Trauma
Preventing physical trauma from scratching is a highly effective way to eliminate direct entry points for bacteria. Keeping fingernails trimmed short minimizes the damage caused by involuntary scratching, especially during sleep. Wearing cotton gloves or mittens overnight can also serve as a physical barrier against scratching.
Trigger Avoidance
Identifying and avoiding personal triggers that cause eczema flares can indirectly reduce infection risk. When eczema is well-controlled, the skin barrier is stronger and less likely to be colonized by S. aureus. Common triggers include certain detergents, fabrics, or environmental allergens.
Treating Staph Infections in Eczema
Once the signs of a secondary staph infection are present, medical consultation is required, as the infection will not resolve with standard eczema treatments alone. A healthcare provider will confirm the diagnosis and determine the appropriate course of action to prevent the infection from spreading or worsening the underlying eczema.
The primary treatment involves antibiotics, chosen based on the severity and extent of the infection. For localized or mild infections, a topical antibiotic ointment, such as mupirocin, may be prescribed. Widespread or severe infections, especially those accompanied by fever or signs of systemic illness, usually require a course of oral antibiotics to clear the bacteria from deeper tissues.
It is necessary to continue eczema maintenance therapy alongside the antibiotic treatment. Topical corticosteroids, when applied to uninfected areas, reduce the underlying inflammation, helping to restore the barrier function. For recurring infections, physicians may implement long-term decolonization protocols, sometimes involving nasal antibiotic ointments and antiseptic washes, to suppress the S. aureus reservoir.