The MC1R gene is one of the genes that regulate melanin synthesis. It is, therefore, responsible for lighter or darker skin and specific hair colour. A mutation in this gene, common in the Mediterranean region, explains why Mediterranean people have a skin that tans easily in summer despite being fair.
According to a study of over 1,000 individuals from different regions undertaken by the Spanish universities, Universitat Jaume I de Castelló and the University of the Basque Country, and published in Molecular Biology and Evolution, the V60L mutation in the MC1R gene is present in 10% to 20% of the population and is estimated by these researchers to have developed around 30,000 to 50,000 years ago. Directly associated with fair skin and fair and red hair, presence of the mutation has both an upside and a downside. On the one hand, it is positive, because being whiter aids vitamin D synthesis (necessary for growth) during winter and also provides some protection in summer given its ability to darken pigmentation; on the other hand, however, individuals with this mutation are also more likely to develop skin cancer. For researchers, this discovery may prove very useful from a medical prevention perspective.
The fever blisters or cold sores that typically appear on the lips are manifestations of the herpes virus, which can also affect the skin elsewhere. Herpes is an extremely common viral infection and, although rarely serious, it causes major discomfort and is also anti-aesthetic. Even more bothersome is the fact that cold sores usually recur over a lifetime.
Herpes labialis is an infection caused by the herpes simplex virus, whose symptoms are observed mainly in the skin and the mucous membranes. It is usually acquired in childhood, so by adulthood most individuals have had contact with the virus. Cold sores on the lips are, in fact, just one of the manifestations (although the most common by far) of herpes simplex infection; the virus can also cause eye problems, affect the inside the mouth or the genitals and even cause more serious problems (meningitis). Read More
The term transmits the accompanying sensation well. Alternatively called cutaneous horripilation or piloerection, this condition develops when we feel fear, cold or an emotion that affects us deeply. This is what we refer to as goosebumps. But why do they develop?
Goosebumps are a manifestation of cold on the skin, a reflex inherited from our ancestors aimed at maintaining body temperature and also warning of danger. Goosebumps are triggered by adrenaline – a hormone produced by the adrenal glands – sending an alert message to the body. The hair reacts by bristling, except in the area of the genitals. This reaction occurs because of the contraction of a muscle called the erector muscle (or arrectores pilorum), situated near the hair follicle – that is, near the roots of the hairs that cover the skin mantle. The pores close in response and the skin forms a small swelling around the hair follicle, resulting in what we call goosebumps — maybe because they remind us of the skin of plucked chickens.
The term “stria” refers to a line, groove or ridge in a surface. Striae now refer to the marks that appear in the skin when it stretches and tears. Appearing in adolescence, as a consequence of pregnancy and when weight is gained or lost, they are difficult to hide. All kinds of creams and other more drastic solutions to combat them are offered in the market. But is it really possible to remove them?
When stretch marks first appear, they are reddish or violet coloured but they eventually become whiteish to the point where they seem to be simple scratches. Their name directly reflects their origin in an overstretching of the dermis due to changes in the body. However, they are caused in different ways. In the early twentieth century they were attributed to infections such as tuberculosis or typhoid. Later they were also associated with malnutrition and toxic states. Most contemporary theories link them to hormones, specifically glucocorticoids (cortisol, basically), which affect the formation of collagen and elastin, both necessary to keep the skin elastic. Some experts, in the absence of other evidence, blame the genes. Read More