Both UVA and UVB rays have detrimental effects on the skin but the intensity of UVA rays is more consistent throughout the day whereas the intensity of UVB fluctuates. The sun protection factor (SPF) ranking system for sunscreens is based on the level of UVB protection the product offers. However, products containing the UVA protection symbol have to provide a minimum level of UVA protection. The ratio should be 1:3 for UVA: UVB protection. It is therefore important to find out the intensity of UV light in your area each day and apply an appropriate level of UV protection. The European Cosmetics Trade Association (formerly Colipa) has also set UV-protection standards for sunscreens. International Standard ISO 24444-2010 is a reliable method of testing the UV efficacy of sunscreen products, and is in line with EU Commission.
Even if you have carefully practiced sun safety all summer, it's important to continue being vigilant about your skin in fall, winter, and beyond. Throughout the year, you should examine your skin head-to-toe once a month, looking for any suspicious lesions. Self-exams can help you identify potential skin cancers early, when they can almost always be completely cured. First, for a successful self-exam, you obviously need to know what you're looking for. As a general rule, to spot either melanomas or non-melanoma skin cancers (such as basal cell carcinoma and squamous cell carcinoma), take note of any new moles or growths, and any existing growths that begin to grow or change significantly in any other way. Lesions that change, itch, bleed, or don't heal are also alarm signals. It is so vital to catch melanoma, the deadliest form of skin cancer, early that physicians have developed two specific strategies for early recognition of the disease: the ABCDEs and the Ugly Duckling sign.
Moles, brown spots and growths on the skin are usually harmless — but not always. Individuals with higher risks of melanoma must be vigilant in doing skin checks. The first signs can appear in one or more atypical moles. That's why it's so important to get to know your skin very well and to recognize any changes in the moles on your body. Look for the ABCDE signs of melanoma, and if you see one or more, make an appointment with a physician immediately.
A = Asymmetry
One half is unlike the other half.
B = Border
An irregular, scalloped or poorly defined border.
C = Color
Is varied from one area to another; has shades of tan, brown or black, or is sometimes white, red, or blue.
D = Diameter
Melanomas are usually greater than 6mm (the size of a pencil eraser) when diagnosed, but they can be smaller.
E = Evolving
A mole or skin lesion that looks different from the rest or is changing in size, shape or color.
The "Ugly Duckling" Sign
Most moles and spots on your body are the same or are similar-looking to each other. The method behind the Ugly Duckling Sign is for you to compare your moles with each other. If any mole stands out or looks different from that of surrounding moles, it is the ugly duckling. An ugly duckling may be a single large dark mole in amongst a sea of smaller lighter moles, or it could be a single small light mole in amongst a sea of large dark moles. The point is that it sticks out from the rest of the crowd.
If you find an ugly duckling mole with any of the ABCDEs, you should get it checked out by a doctor immediately.
Three Examples of an Ugly Duckling
Three different clinical scenarios are shown where outlier lesions (" ugly ducklings ") should prompt suspicion. Squares A, B, and C each represent a body area such as the back. In A, the patient has one dominant mole pattern with slight variation in size. The outlier lesion is clearly darker and larger than all other moles. In B, the patient has two predominant nevus patterns, one with larger nevi and one with small, darker nevi. The outlier lesion is small but lacks pigmentation. In C, the patient shows only one lesion on the back. If this lesion is changing, symptomatic, or deemed atypical, it should be removed.