Eczema is a fairly common inflammatory disease. The most well-known symptoms of eczema are the appearance of red patches on the skin and sensations of itching. It is also sometimes said that this condition can leave brown spots. What is the reality of this?
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Can eczema leave brown spots?
Summary
Published September 20, 2023,
updated on June 28, 2024,
by
Pauline, Chemical Engineer
—
4 min read
What are the causes of the appearance of brown spots?
Brown spots form as a result of melanin accumulation in the skin. This dark brown pigment is essential and plays a protective role against UV rays. However, it can impact the uniformity of the complexion in case of overproduction. The primary cause of brown spots is exposure to the sun's rays: we refer to these as solar spots. Indeed, UV rays act on tyrosine, an amino acid, and, thanks to the enzyme tyrosinase, trigger a cascade of reactions leading to the synthesis of melanin. This process is melanogenesis. That's why it's important to apply sunscreen daily. Tobacco and pollution can also contribute to the appearance of brown spots, as these elements generate oxidative stress in the body's cells.
Hyperpigmentation can also be linked to hormonal changes, particularly during pregnancy. Indeed, pregnancy triggers a significant increase in the levels of estrogen and progesterone in the body, hormones capable of activating melanogenesis. Pigment spots related to this phenomenon are referred to as "pregnancy mask". Lastly, brown spots can form following a skin inflammation or lesions. During an inflammation (acne, burn, injury...), pro-inflammatory cytokines stimulate the activity of melanocytes. This is also true in the case of eczema.
A link between eczema and brown spots?
Eczema is an inflammatory skin condition characterized by red patches, fine blisters, and scales . The skin in areas affected by eczema also tends to become rough, eventually developing crusts and oozing. These various symptoms are accompanied by itching. Eczema is a chronic disease characterized by periods when the lesions worsen, known as eczema flare-ups, and periods of remission. There are several types of eczema , the most common being atopic eczema, which has a genetic component , and contact eczema, also known as allergic eczema.
It happens that eczema leaves scars, sometimes in the form of brown spots. When the skin is irritated or under the effect of scratching, it triggers an inflammatory response, resulting in the release of pro-inflammatory cytokines such as interleukin-1 (IL-1) and tumor necrosis factor (TNF-α). These cytokines then activate the protein kinases A and C (PKA and PKC), molecules that allow the phosphorylation and thus the activation of certain proteins involved in melanogenesis. The melanocytes are then stimulated and the synthesis of melanin begins. Post-inflammatory hyperpigmentation is more common in people with dark skin. Indeed, the main form of melanin produced by these people is the eumelanin, the darkest form of pigment. This increases the risks of brown spots.
Sources
GOLDENBERG G. & al. Eczema. The Mount Sinai Journal of Medicine (2011).
BORRADORI L. & al. Dermatologie et infections sexuellement transmissibles. Elsevier Masson (2017).
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