The skin, a visible organ and the largest in the human body, protects us from the external environment and can also reveal much about what is happening in the body. Changes in the skin can be a consequence of external aggressions, but they can also be associated with benign and common diseases and more serious health problems, including cancer. Not all skin changes mean cancer, but some are true warning signs. Knowing these signs, being attentive, and seeking medical attention in a timely manner can make all the difference . Diseases that can be reflected in the skin Skin cancer Skin cancer is currently the most common type of cancer worldwide. Its incidence has increased in recent decades, including in Portugal, where approximately 12-13 thousand new cases are diagnosed every year. This increase is related to several factors, for example: The aging of the population; Greater accumulated sun exposure throughout life; Outdoor leisure habits; Improved dermatological surveillance and diagnosis. Despite everything, when detected early, the cure rate for many skin cancers is high . There are three main types of skin cancer. Basal cell carcinoma is the most frequent and is characterized by slow growth and a low probability of metastasis, although it can cause local destruction if left untreated. Squamous cell carcinoma has the greatest capacity for invasion and spread to other organs. Melanoma , although less common, is the most aggressive type and is responsible for most deaths associated with skin cancer. Cancer in other tissues and organs In addition to being a site where primary tumors appear, the skin can also reflect internal oncological diseases . In some cases, tumors in other organs cause skin changes, such as metastatic nodules or paraneoplastic syndromes. Skin changes like these can even be the first warning sign leading to the diagnosis of internal organs cancer. Other diseases Besides oncological diseases, many others, in various stages of their evolution, can cause skin changes. These include: Infectious diseases , such as syphilis, measles, chickenpox, human immunodeficiency virus infection, candidiasis, meningitis, among others; Autoimmune and immune-mediated diseases , for example, lupus and psoriasis; Metabolic diseases , such as diabetes and dyslipidemia; Hematological diseases , for example, anemia; Vascular diseases , for example, chronic venous insufficiency; Nutritional deficiencies , including deficiencies in iron, zinc and vitamin A; Addictions , such as alcoholism. Cancer treatments Oncological treatments, such as chemotherapy, radiotherapy, immunotherapy, or targeted therapies, can also have effects on the skin. Among the most common changes are: Dry skin; Acne-like eruptions; Hyperpigmentation; Hair loss; Nail changes; Increased sensitivity to sun exposure; Skin inflammation in treated areas. These changes, although often temporary, impact quality of life . Warning signs on the skin Observe your skin regularly and check for warning signs : ABCDE rule: A symmetrical moles, with irregular B orders, multiple C olors, D iameter greater than 6 millimeters and/or that have undergone E volution (change in size, color and/or shape); Moles with a different appearance from others (the "ugly duckling" sign); Rough or scaly lesions (sometimes can be felt before being visible); Moles that cause itching; Lesions that bleed or release fluid; Pinkish papules/nodules; Lesions that look like a wound but don't heal. Is the risk of skin cancer the same for everyone? No, the risk is particularly high when: The skin is fair or prone to sunburn; Sunburns occurred in childhood; There is a history of significant sun exposure, whether associated with work or leisure; There is periodic sun exposure, for example, on vacation; Using tanning beds; There are more than 50 moles on the body; There is a family history of skin cancer; You are over 50 years old; If you have had an organ transplant. Prevention is key Essential measures to prevent skin cancer include: Avoiding excessive sun exposure, especially sunburns; Using adequate sunscreen; Wearing protective clothing, including protecting the head with a hat or cap; Avoid using tanning beds; Regular self-examination of the skin and regular check-ups with a dermatologist help to identify any suspicious lesions early. How is skin cancer treated? Surgery is often the first treatment option for skin cancers. In most cases, when performed in a timely manner, it allows for a complete cure of the disease. Other approaches include topical therapies, cryotherapy, radiotherapy, immunotherapy, or targeted therapies. The skin can be a true mirror of health Recognizing warning signs and seeking medical attention quickly when signs are detected or there is any doubt can make all the difference in the prevention and treatment of skin cancer. Therefore, if you have a skin lesion that looks suspicious, don't assume that "it must be nothing serious" or wait to see how it evolves: talk to your doctor or consult a dermatologist . Author : Paulo Morais (dermatology) Meet the dermatology clinical team from Hospital da Luz network. The content published in the Health Guide is intended for the general public and is provided for informational and educational purposes only. It does not replace individual medical assessment, diagnosis, or personalized clinical advice from a qualified healthcare professional. The content is produced or reviewed by physicians and other healthcare professionals at Hospital da Luz and is based on the knowledge available at the time of publication or the most recent update, as indicated at the beginning of each item.
