The Link Between Staphylococcus aureus and Eczema
Bacterial, fungal, and viral skin infections are common complications associated with eczema. Skin lesions provide entry points for opportunistic microorganisms to penetrate the skin, proliferate, and cause infections.
Of particular concern for people with eczema is that their skin is frequently colonized with the bacteriumStaphylococcus aureus (S. aureus). Although it is normal for staphylococcal bacteria to live on skin lesions, on intact healthy skin, or in the nose, studies have shown that individuals with eczema are more common carriers of S. aureus than those who do not have this condition. It has been speculated that one of the main reasons for this increased prevalence is that people with eczema lack certain immune defenses, such as the production of antimicrobial peptides, which enable the body to combat and control the growth of microorganisms.
Flare-ups and Infections
S. aureus bacteria can live on the skin without causing any apparent symptoms; however, certain conditions that allow overgrowth to occur can create the potential for flares and infection.
S. aureus infection may be a frequent cause of eczema flares. Although colonized skin may show no obvious signs of infection, S. aureus can still trigger flare-ups by stimulating the immune system to produce certain antibodies that contribute to eczema.
In addition, itching and scratching can further impair the already weakened skin barrier and cause flare-ups of eczema that can result in secondary infections. This itch-scratch cycle causes tissue damage that encourages the overgrowth of S. aureus, leading to infection and the worsening of inflamed lesions.
A study investigating the link between S. aureus colonization and hand eczema (HE) severity found that almost half (48%) of the study participants with HE were infected with S. aureus. Furthermore, bacterial colonization of the hands by S. aureus was observed to be related to the severity of this skin disease. Patients with HE were six times more likely to be hand and nasal carriers of this specific strain of staphylococcal bacteria than other individuals. [Haslund P, et al. Staphylococcus aureus and hand eczema severity. Br J Dermatol 2009 Oct;161(4):772-7.]
Researchers also suggest that the effects of S. aureus in patients with HE and its relationship to eczema severity indicate that S. aureus could be an additional factor in explaining why the disease maintains a relapsing and chronic path. The study investigators propose that given their findings “Future studies, including intervention with antibiotics, are necessary to conclude if S. aureus is a cause or a consequence of HE.”
The severity of both eczema and staph infections frequently correlates with the extent of bacterial colonization. Therefore, individuals who experience frequent flare-ups may need strategies to reduce S. aureus colonization and inflammation.
When there is an absence of any clear visual indications, a likely sign that bacterial colonization is present includes a worsening of eczema that is not responsive to standard therapy. In contrast, areas of obvious infection can appear as wet, oozing, pus-filled, or crusted lesions that require management with topical or oral antibiotics.
Most people with eczema who develop a staph infection can be treated effectively with topical combination therapy consisting of a corticosteroid and an antibiotic. Only if recommended by the treating physician, taking antiseptic baths may be helpful for reducing the number of staph bacteria on the skin. Systemic antibiotics are generally used to treat larger areas of infected eczema. Severe infections may require oral antibiotics or even a prolonged course of antibiotics. However, the increase in antibiotic-resistance to methicillin or topical antibacterials, such as fusidic acid and mupirocin, is of growing concern in the treatment of S. aureus infections. As such, it is important for patients to strictly adhere to the instructions for use and complete the prescribed course of treatment.
Prompt recognition of flares and staph infections can lead to the initiation of early combined topical therapy. Such timely intervention can potentially avoid or limit the need for antibiotics in mild-to-moderate eczema and prevent flares from progressing to more advanced stages.
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