Aside from being the largest organ in the body, our skin is a dynamic network of cells that is constantly changing.
Consequently, changes in our skin can sometimes be a harbinger of more sinister issues occurring in the body, such as infections or cancer.
Being able to identify these skin conditions could allow you to seek early treatment and improve your prognosis.
Here are four common medical conditions that can affect your skin:
Hyperlipidaemia (high cholesterol) and diabetes are two common chronic diseases that can result in skin changes.
However, these changes tend to form over time and evolve slowly.
For patients with hyperlipidaemia, an elevated level of cholesterol in the blood increases the risk of atherosclerotic plaques forming in the blood vessels.
This blocks blood flow to major organs, including the heart and brain, and can result in a heart attack or stroke.
Hyperlipidaemia can also cause fleshy, non-painful lumps called xanthomas.
These can appear anywhere on the body, even on the eyelids.
In diabetes, the body is unable to process blood glucose, resulting in a dysfunction in many metabolic processes.
This has a knock-on effect on many organs, including the skin.
Patients who have diabetes have characteristic skin changes known as acanthosis nigricans.
This is a dark discoloration of the skin, especially along the neck, armpits and groin areas.
Skin changes related to infections tend to be more rapid in onset compared to those from chronic disease.
Syphilis can cause different skin changes, depending on the stage of the disease.
For primary syphilis – defined as nine to 90 days post exposure – patients usually present with a painless ulcer, most commonly around the genitals.
The ulcer usually heals by itself and the disease can stay latent for some time.
Secondary syphilis, which is a stage of the disease that occurs six weeks to six months after exposure, causes an extensive rash throughout the body.
The rash is characteristically painless, symmetrical and most obvious on the palms and feet.
Skin cancer is commonly caused by excessive sun exposure.
These cancerous lesions generally do not resolve, but rather, tend to be non-healing and enlarge over time.
The three common skin cancers are basal cell carcinoma, squamous cell carcinoma and melanoma.
Basal cell carcinoma is common in patients with fair skin.
The lesions from this cancer are usually translucent or pearly with small red spots from the internal blood vessels.
Squamous cell carcinoma is less common, but more aggressive, and can grow rapidly if left untreated.
The lesions for this cancer are hard, nodular and tend to increase in size rapidly. They also tend to bleed easily.
Melanoma is the most dangerous of all skin cancers.
The lesions tend to look like new moles that change in appearance and start bleeding or crusting.
Skin changes are an important bellwether that can point towards diseases we may have, but not yet have any other symptoms from.
Understanding common skin changes associated with these diseases is important to ensure that you see your doctor and get treatment early.
Dr Matthew Tan is a general practitioner (GP) in Singapore. For more information, email firstname.lastname@example.org. The information provided is for educational purposes only and should not be considered as medical advice. The Star does not give any warranty on accuracy, completeness, functionality, usefulness or other assurances as to the content appearing in this column. The Star disclaims all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.