Is it a rash or is it skin cancer?

Examining yourself in the mirror one morning, you notice a new rash on your upper body that’s making your skin red and itchy. Not exactly great news, but don’t panic.

Skin rashes are often harmless. They can be the result of a reaction to a plant like poison ivy, heat, or a new detergent. Infections, allergens, or immune system disorders can also play a role.

While many rashes can be easily managed, some can be a sign of a bigger problem, as certain types of skin cancer can appear as a rash. But how can you tell the difference between a rash that was caused by irritation, and one that’s a more urgent concern?

Detecting skin cancer early

The best way to detect skin cancer early is simply to be familiar with your full body so that you can spot new or unusual growths, or changes in the shape, colour, or size of an existing mark. 

If you find a rash on your body that isn’t going away over time, speak to a doctor or a dermatologist. Avoid jumping to conclusions – many rashes are noncancerous. A trained healthcare professional can recognize skin cancer and properly diagnose the issue.

While many cancers develop where they can be easily seen, facilitating early detection, they can also develop in more hidden areas. Make sure to look at different parts of your body, including:

• Your face
• Neck
• Trunk
• Arms
• Legs 
• Between your toes
• Underneath your nails
• The soles of your feet
• Your genitals

Skin rashes, cancer, and skin conditions

Skin cancer can initially appear as a rash, a lump, or an abnormal patch on the surface of the skin. These marks can bleed, ooze, and change in appearance over time. The most common forms of skin cancer – or conditions that can become skin cancer – include:

Basal cell carcinomas

A type of skin cancer that can appear as pink, red, or shiny growths on your skin. If it develops around the chest area, it can look like a skin-coloured lesion or a brown scar. Caused by exposure to the sun, this type of cancer rarely spreads, but can leave permanent scars if not treated properly.

Squamous cell carcinomas

A type of cancer that can develop as a rough lump on the surface of the skin. Unlike a skin rash that heals over time, these reddish patches will continue to develop slowly, so make sure to consult a doctor or a dermatologist.

Merkel cell carcinomas

A less common form of cancer that can appear as red or skin-coloured nodules. They are usually found on parts of the body that are regularly exposed to the sun, like your face, scalp, or neck.

Actinic keratoses

Dark or skin-coloured marks that can appear on your face, neck, scalp, shoulders, or other parts of your body that receive a lot of sun exposure. It can take years for these patches to develop, so they’re usually a concern for people over the age of 40. A small percentage of these types of lesions can become skin cancer over time. To reduce your risk, protect your skin from ultraviolet (UV) rays by wearing sunscreen on non-covered areas, wearing long sleeves and pants, and seeking shade.

Actinic cheilitis

These appear in the form of sores or bumps on your lower lip. Your lip can also become red or swollen. Caused by long-term sun exposure, these bumps can turn into squamous cell carcinomas over time.

Cutaneous horns

These are painful growths that are made from keratin, the protein that forms hair, skin, and nails. As the name suggests, cutaneous horns look a little like animal horns. They often grow out of cancerous or precancerous skin sores, so speak with a trained healthcare professional.

Moles

These are individual growths that are often benign. They can also be a sign of melanoma, a serious form of skin cancer. Moles can be black, brown, red, pink, or skin-coloured. Seek advice from a doctor or dermatologist if:

• One side of your mole looks different from the other. 
• A mole has turned more than one colour.
• Your mole is dark in colour.
• Your mole is larger than 6 millimeters in width. 
• The border of your mole is fuzzy or irregular.
• Your mole is changing in appearance.

Preventing skin cancer

Simple steps to protect your skin can help prevent skin cancer. Try:

1. If you can, stay indoors during the day when the sun’s ultraviolet rays are at their strongest, from mid-morning to late afternoon.
2. If you have to go outside, apply sunscreen to all exposed areas, including your lips and eyelids. Use a broad-spectrum (UVA/UVB) SPF30. Make sure to reapply after a swim or if you’re sweating a lot.
3. Wear clothing that protects you from the sun, like a bucket or broad-brimmed hat that can shield your face and neck. Cover your arms and legs with long clothing.
4. Avoid tanning, either in a tanning bed or by staying outside. Even if you tan naturally, tanning damages your skin and increases your risk of melanoma.

Many cancers cause rashes that can resemble less serious skin conditions, so discussing changes in your skin with an experienced healthcare professional can make a big difference.
If you suspect something’s wrong, don’t wait. The sooner skin cancer is diagnosed, the better the chances are of curing it. 

Got a rash you’re not sure about? You can speak with a doctor or a dermatologist from anywhere using your phone, tablet, or computer.