How to spot 18 common — and not so common — bumps, rashes and growths

Summer ushers in a bevy of skin-related issues from bug bites to heat rash. While a mosquito bite is a temporary, albeit itchy annoyance, skin disorders can vary in both symptoms and severity. Is it acne, a rash — or maybe something more serious? Some skin conditions are minor, some are serious but treatable, and others, like skin cancer, can be life-threatening. That's why it's important to take the proper precautions to keep your skin safe by using sunscreen, limiting your time in the sun and wearing sun protective clothing.

Here are 18 common (and a few less common) skin conditions — with photos to help you ID them.

Acne | Actinic keratosis | Basal cell carcinoma | Blisters | Carbuncle | Cellulitis | Chicken pox | Cold sores | Contact dermatitis | Eczema | Hives | Latex allergy | Lupus | Measles | Melanoma | Psoriasis | Rosacea | Squamous cell carcinoma

Acne

Suffering from acne? You’re not alone. Acne is the most common condition dermatologists treat — 40 to 50 million Americans struggle with acne at any given time.

Photos of acne

Acne symptoms and signs

Acne can show up almost anywhere on the skin — as blackheads, papules and pustules or pimples, cysts and nodules

Causes of acne

Acne starts when dead skin cells don’t shed properly and clog your pores.

Acne treatments

Some acne can be treated with over-the-counter products, while others require professional help, including prescription medication and treatments.

Read more about acne and how to treat it.

Actinic keratosis

These precancerous lesions often appear as rough spots on the skin. Actinic keratosis is common, but if left untreated it can turn into squamous cell carcinoma.

Photos of actinic keratosis

Actinic keratosis symptoms and signs

The appearance of actinic keratosis can vary from bumps that look like pimples or acne to rough lesions that are red, pink or gray.

Causes of actinic keratosis

When cells in the skin called keratinocytes are damaged by UV rays, it can cause actinic keratosis.

Actinic keratosis treatments

While not always necessary, treatments may include removal of the actinic keratosis with liquid nitrogen, chemical peels, scraping or other therapies.

Read more about actinic keratosis and how to treat it.

Basal cell carcinoma

Basal cell carcinoma is the most common type of skin cancer. It affects approximately 2.6 million people in the U.S. each year. Do you know how to spot it?

Photos of basal cell carcinoma

Basal cell carcinoma symptoms and signs

Basal cell carcinoma is much more common in people who have light skin. Symptoms tend to be the same color as the skin — or pink. It’s important to look for any changes in your skin.

Causes of basal cell carcinoma

Exposure from ultraviolet rays (UV) from the sun or indoor tanning is a primary cause of basal cell carcinoma.

Basal cell carcinoma treatments

Your dermatologist may be able to remove a basal cell carcinoma tumor when doing a biopsy. Sometimes a Mohs surgery is recommended.

Read more about basal cell carcinoma and how to spot it.

Blisters

A common skin condition, most people develop blisters once in a while.

Photos of blisters

Blisters symptoms and signs

Blisters are small, painful sacs of fluid.

Causes of blisters

Blisters can be caused by friction, such as by a shoe rubbing against the skin, or by sunburns, heat or skin diseases.

Blisters treatments

Blisters tend to heal on their own, but a blister can be drained if it’s too painful.

Read more about blisters and how to treat them.

Carbuncle

Sometimes confused with a spider bite, a carbuncle is a group of boils that stem from an infection of the skin and are connected to each other.

Photos of carbuncles

Carbuncle symptoms and signs

Red, tender bumps, or boils, that contain pus are signs of a carbuncle. Carbuncles can eventually rupture, and pus will leak out of them.

Causes of carbuncles

A bacterial infection, such as Staphylococcus aureus, is often the cause of a carbuncle.

Carbuncle treatments

If a carbuncle is small, you may be able to treat it at home with warm compresses and bandages. Otherwise, your dermatologist can make an incision to drain the pus.

Read more about carbuncles and how to treat them.

Cellulitis

Cellulitis is an infection of the skin in which the skin becomes red and swollen. It typically occurs after you get a cut or wound.

Photos of cellulitis

Cellulitis symptoms and signs

When you have cellulitis, an area of your skin — often on one of your legs — becomes red, swollen, warm and possibly painful.

Causes of cellulitis

Cellulitis can be caused by two different types of bacteria: streptococcus (aka strep) or staphylococcus (aka staph).

Cellulitis treatments

Antibiotics like penicillin, cephalosporin or erythromycin are normally used to treat cellulitis.

Read more about cellulitis and how to treat it.

Chicken pox

Also called varicella, this highly contagious disease mostly strikes children.

Photos of chicken pox

Chicken pox symptoms and signs

A fever may precede it, but the unique chicken pox rash appears on the skin with itchy blisters that look like lots of little dew drops.

Causes of chicken pox

The varicella-zoster virus (VZV) causes chicken pox — as well as shingles. It’s unlikely to get chicken pox if you’ve had the chicken pox vaccine.

Chicken pox treatments

The best treatment for chicken pox is prevention through vaccination. An early case of chicken pox may be treated with antiviral drugs. Other remedies can be used to ease symptoms.

Read more about chicken pox and how to treat it.

Cold sores

Also known as fever blisters, cold sores are blisters, or clusters of blisters, that appear on your lips or near your mouth.

Photos of cold sores

Cold sores symptoms and signs

Symptoms of cold sores can vary. The sores may start with a tingling, burning or other sensation, then break open and scab over.

Causes of cold sores

Cold sores are caused by the herpes simplex virus. Outbreaks are triggered by stress, fatigue, illness and other factors.

Cold sores treatments

Read more about cold sores and how to treat them.

Contact dermatitis

Almost everyone gets contact dermatitis at some point. There are two main types of contact dermatitis — allergic and irritant. Both trigger a rash.

Photos of contact dermatitis

Contact dermatitis symptoms and signs

Symptoms of allergic contact dermatitis may include itching, rash, dryness and other symptoms. Cracked, itchy, chapped skin with sores may be signs of irritant contact dermatitis.

Causes of contact dermatitis

Contact dermatitis is caused by something that touches your skin — like poison ivy, nickel, fragrances, latex or other irritants — and triggers a rash.

Contact dermatitis treatments

The best treatment for contact dermatitis is to avoid whatever it is that triggers your rash. Beyond that, your dermatologist may also recommend antihistamine pills, moisturizers or topical steroids.

Read more about contact dermatitis and how to treat it.

Eczema

Eczema is a condition that causes red, itchy patches on the skin. It often starts at a young age — often people with eczema get it when they're babies.

Photos of eczema

Eczema symptoms and signs

Eczema is almost always itchy, but otherwise symptoms can vary from person to person. Skin infected with eczema can be dry, dark, scaly, swollen or oozing.

Causes of eczema

Eczema may be caused by an overactive immune system, but it’s not entirely clear what causes the condition.

Eczema treatments

There is no cure for eczema, but symptoms can be managed with medications and other therapies.

Read more about eczema and how to treat it

Hives

The onset of hives can be mysterious, and though hives usually go away in less than 24 hours, new ones can repeatedly appear.

Photos of hives

Hives symptoms and signs

Hives appear on the skin as slightly swollen, raised pink or red patches. You may have one hive, a group of hives that may be separate or connected together.

Causes of hives

It’s difficult to pinpoint the cause of hives, but there are many triggers that can cause hives, from insect bites and allergic reactions to medication, stress and heat.

Hives treatments

The go-to treatment for hives is usually antihistamines.

Read more about hives and how to treat them.

Latex allergy

People with an allergy to latex are allergic to a protein found in the sap of the Brazilian rubber tree.

Photos of latex allergy

Latex allergy symptoms and signs

Different symptoms appear with different types of latex allergies. One type causes a rash on the skin; another can cause anaphylaxis, which can result in a swelling of the airways and difficulty breathing.

Causes of latex allergy

When your immune system reacts as though latex is a harmful substance, it causes an allergic reaction to latex.

Latex allergy treatments

Since there’s no cure for latex allergies, your best bet is to avoid coming into contact with latex.

Read more about latex allergy and how to treat it.

Lupus

An autoimmune disease that causes pain and inflammation, lupus can affect your skin, as well as your kidneys, heart, joints and lungs.

Photos of lupus

Lupus symptoms and signs

A red butterfly-shaped rash that appears on the nose and cheeks is one common sign of lupus, but symptoms of lupus will vary, depending on the type of lupus you have.

Causes of lupus

There are a number of factors that may play a role in whether you develop rosacea, but experts don’t know for certain what causes the skin condition.

Lupus treatments

There is no cure for rosacea, but the condition can be managed to help keep symptoms from worsening.

Read more about lupus and how to treat it.

Measles

Also known as rubeola, measles is a contagious — and potentially deadly — disease that usually strikes children.

Photos of measles

Measles symptoms and signs

Beyond the signifying red, spotted rash, measles may also be accompanied by a fever, cough, runny nose and other symptoms.

Causes of measles

A virus that infects the respiratory tract and spreads throughout the body causes measles. It’s one of the most contagious diseases.

Measles treatments

The best treatment is prevention through a vaccine. Otherwise, high doses of vitamin A, bed rest and medications to reduce pain and fever may help.

Read more about measles and how to treat it.

Melanoma

It’s one of the less common skin cancers, but melanoma is the most dangerous because it can easily spread to other parts of your body.

Photos of melanoma

Melanoma symptoms and signs

Melanoma tumors tend to be black or brown, but can sometimes be pink, tan or white. Anyone can get melanoma, but people with light skin are at greater risk.

Causes of melanoma

UV light exposure from ultraviolet rays from the sun or indoor tanning causes most melanomas.

Melanoma treatments

Treatments depend on how advanced the melanoma is and where the tumor is located. It may include surgery, radiation, chemotherapy or other therapies.

Read more about melanoma and how to treat it.

Psoriasis

Psoriasis affects more than 8 million people in the U.S. It typically starts in the teen years or early 20s, though it can occur at any age.

Photos of psoriasis

Psoriasis symptoms and signs

When you have psoriasis, your body makes new skin cells quickly, and the cells typically build up in thick, scaly patches on the skin called plaques.

Causes of psoriasis

There are a number of factors that may contribute to causing psoriasis. The immune system and genetics may play a role. Certain triggers can also cause the onset of psoriasis and psoriasis flare-ups.

Psoriasis treatments

Psoriasis doesn’t have a cure, there are medications and treatments that can help manage the condition.

Read more about psoriasis and how to treat it.

Rosacea

This common inflammatory skin condition causes redness of the face.

Photos of rosacea

Rosacea symptoms and signs

In addition to causing facial redness, if rosacea is not treated, it can cause visible blood vessels, breakouts like acne and other symptoms.

Causes of rosacea

There are a number of factors that may play a role in whether you develop rosacea, but experts don’t know for certain what causes the skin condition.

Rosacea treatments

There is no cure for rosacea, but the condition can be managed to help keep symptoms from worsening.

Read more about rosacea and how to treat it.

Squamous cell carcinoma

Also known as cutaneous squamous cell carcinoma, this cancer develops when the squamous cells in the top layer of your skin grow out of control.

Photos of squamous cell carcinoma

Squamous cell carcinoma symptoms and signs

Though it’s linked with exposure to ultraviolet rays, squamous cell carcinoma can crop up in areas that don’t get much sun. Watch out for rough, scaly patches, sores that don’t heal or anything else that looks suspicious.

Causes of squamous cell carcinoma

Squamous cell carcinoma is mainly caused by UV rays from the sun or indoor tanning.

Squamous cell carcinoma treatments

Treatments for squamous cell carcinoma may include surgery, radiation or other therapies. Catching it early is key.

Read more about squamous cell carcinoma and how to treat it.

How to identify a skin condition

Although these photos can help you potentially spot and identify some skin conditions, remember to always reach out to your physician for a proper diagnosis and treatment. Often, a doctor or dermatologist can diagnose a skin condition by just looking the affected area, according to the Cleveland Clinic. If that doesn't yield a diagnosis, the doctor may order tests which include biopsies, skin patch allergy tests and other diagnostic tools.

This article was originally published on TODAY.com