If you live with hidradenitis suppurativa (HS), a new painful bump may look like part of a flare. But some skin infections, including those caused by methicillin-resistant Staphylococcus aureus (MRSA), can cause similar redness and skin discoloration, swelling, pain, and drainage.

HS is a chronic inflammatory skin condition. MRSA is a type of staph bacteria resistant to methicillin and related antibiotics. It can cause skin and other infections.

Because you can’t tell whether a skin infection is caused by MRSA based on symptoms or appearance alone, knowing how HS and MRSA skin infections tend to differ can help you recognize changes that may need medical attention.

How Do HS and MRSA Skin Infection Symptoms Differ?

HS causes repeated, deep, painful lumps or abscesses, often in areas where skin rubs together, and it isn’t contagious. An MRSA skin infection can cause a red or discolored, swollen, warm, pus-filled bump. MRSA can spread through contact with infected skin, wounds, or contaminated items.

Here are some key differences between the two.

HS often causes painful lumps deep in the skin. These lumps usually develop where skin touches skin, such as the armpits, groin, and inner thighs. HS is also common under the breasts, on the genitals, and on or between the buttocks. The lumps may clear for a while and then come back to the same area.

MRSA skin infections can also cause bumps, but they’re caused by bacteria rather than the inflammation associated with HS. An MRSA skin infection may develop where the skin is broken, such as around a cut, scrape, or open wound.

An MRSA skin infection may cause a bump or sore that’s red, swollen, painful, warm, or filled with pus or drainage. These skin changes can look like boils, spider bites, or other skin problems. A person with an MRSA skin infection may also develop a fever.

HS can also cause painful lumps and abscesses, but it’s not caused by an infection or poor hygiene. However, skin affected by HS can develop a bacterial infection, so it’s important to pay attention if a bump looks or feels different from your usual HS symptoms.

HS may start with discomfort before a lump appears. Some people notice burning, itching, sweating, or swelling in the area before they see a bump. As HS progresses, lumps can grow, join together, drain blood or pus, heal slowly, and return.

Repeated healing and reopening can cause tunnels beneath the skin and permanent scars. These deeper, recurring changes are more characteristic of HS than of a single MRSA skin infection.

How Diagnosis and Treatment Differ

HS and MRSA skin infections can sometimes look similar, but healthcare providers diagnose and treat them differently. Testing can help determine whether MRSA is causing an infection, while HS is usually diagnosed based on symptoms and a skin exam.

HS Is Diagnosed Based on Symptoms and a Skin Exam

MRSA is diagnosed when a healthcare provider sends a sample to a laboratory to see whether MRSA is causing the infection. The sample may include fluid or tissue from the affected area.

HS diagnosis is usually based on a skin exam, your symptoms, where the lesions appear, and whether they keep coming back. A dermatologist may test fluid from a draining bump to check for infection, but there’s no single lab test that confirms HS.

HS and MRSA Skin Infections Need Different Treatment Plans

HS treatment focuses on reducing flare-ups, helping wounds heal, relieving pain and itch, and preventing symptoms from getting worse.

Treatment may include skin care, topical or oral medications, biologics that reduce inflammation, wound care, or in-office procedures for persistent lesions or tunnels.

Treatment for an MRSA skin infection depends on the type and severity of the infection. For some infections, draining the infected area is the main treatment. Antibiotics that work against MRSA may also be needed.

Some people carry MRSA on their skin or in their nose without having symptoms. This is called colonization. People who carry MRSA can later develop an infection. You can ask your healthcare provider about prevention steps if infections keep returning.

When To Call a Doctor

If you live with HS, it can be easy to assume every painful bump is another flare. But a new or fast-changing area of skin deserves attention, especially if it feels different from your usual HS symptoms.

When To Get Medical Attention

Contact your healthcare provider if a bump or sore doesn’t improve within 48 hours or you develop a fever. You should also seek medical care if the area spreads quickly, becomes very painful, or drains pus.

Until you can be seen, don’t pick at or pop the bump, keep it covered with a clean bandage, and clean your hands often.

Because MRSA skin infections, ingrown hairs, boils, and HS can look similar, don’t rely on appearance alone. If you’re unsure what’s causing a new or changing bump, talk with your healthcare provider.

Insights From myHSteam

It’s possible to have both HS and an MRSA infection. Members of myHSteam have shared their experiences with both conditions.

“I’ve had MRSA verified by hospital culture,” one myHSteam member said. “What helped long term was not picking it up in public, as drug-resistant germs can be community-acquired.”

The member also described carrying hand sanitizer and using it after touching public surfaces. MRSA can spread through contact with infected skin, wounds, or contaminated items.

However, MRSA prevention also includes keeping wounds clean and covered, practicing good hand hygiene, and avoiding shared personal items.

Pay Attention to Skin Changes

HS and MRSA skin infections can look similar, but they have different causes and treatments. If a skin change seems different from your usual HS symptoms, talk with your healthcare provider about what may be causing it.