How Common Is Pyoderma Gangrenosum and Who Gets It?

Pyoderma gangrenosum (PG) is a very rare inflammatory skin condition. Despite its name, it is not a contagious bacterial infection ^[1]. Research shows that only about 3 to 10 people per million develop it each year ^[2]. While it can affect anyone at any age, it is most frequently diagnosed in adults—particularly women ^[3][4].

PG involves abnormal immune system inflammation; some people who develop it also have an associated systemic medical condition (like inflammatory bowel disease or arthritis), while others do not ^[5]. Because of this, care is often led by a dermatologist, with other specialists joining the team only if your symptoms or medical history point to another illness ^[3].

Just How Rare is It?

Medical researchers look at how common a disease is in two ways: how many new cases appear each year (incidence) and how many people currently have it (prevalence).

• New cases (Incidence): Worldwide estimates suggest that between 3 and 10 new cases of PG occur per one million people every year ^[2]. To put that in perspective, in a city of one million people, doctors might only see a handful of new cases annually.
• Total cases (Prevalence): A large study of patient records in the United States found that about 5.8 out of every 100,000 adults (or roughly 58 per million) are living with the condition at any given time ^[4].

Because it is so uncommon and can look like ordinary infections or other types of ulcers, PG is notoriously difficult to diagnose and is frequently misdiagnosed ^[1]. There is no single definitive blood test or biopsy that proves a person has PG; instead, doctors must rely on careful clinical assessment and rule out other mimicking conditions ^[6].

Age and Sex Patterns

While pyoderma gangrenosum can strike at any age, there are clear patterns in who is most likely to develop it. However, it is important to remember that these are just general trends—not absolute rules. Anyone of any gender or age can be affected ^[7][8].

• Age: It primarily affects adults. The average age when symptoms first appear is typically in the early 50s, though the highest overall rates are seen in people in their 70s ^[3][4]. It is extremely rare in children, who account for less than 4% of reported cases ^[7].
• Sex: Although men and women both get PG, many studies show it is more common in women ^[4]. In some specialty clinics, up to 75% of patients evaluated for PG were women ^[3]. (Note that statistics from specialty clinics may overrepresent certain groups compared to the general population).

The Link to Other Health Conditions

More than half of all people diagnosed with PG—between 56% and 67% in various studies—have an associated underlying health condition ^[5][3]. These conditions may have been known before the PG appeared, found around the time of diagnosis, or may develop later ^[9].

These estimates often come from overlapping groups of patients at specialized referral centers. The most common associations include:

• Inflammatory Bowel Disease (IBD): Conditions like ulcerative colitis and Crohn’s disease (chronic inflammation of the digestive tract) are the most frequent companions to PG. Studies estimate that between 17% and 41% of people with PG also have IBD ^[5][3]. IBD is particularly common in younger PG patients (under age 65) ^[3].
• Inflammatory Arthritis: About 12% to 20% of people with PG have an inflammatory joint disease ^[5][3]. This refers to autoimmune joint inflammation—with rheumatoid arthritis being the most common type—which is entirely different from common, wear-and-tear osteoarthritis ^[10].
• Blood and Bone Marrow Disorders: Between 5% and 9% of patients have an associated blood or bone marrow disorder ^[5][3]. These range from blood cancers to conditions where blood cells do not form properly, such as myelodysplastic syndrome ^[11][3]. These associations are more common in patients diagnosed with PG at age 65 or older ^[3].
• Solid Tumors: A smaller percentage of patients (around 6% to 7%) have other forms of solid organ cancer ^[5][3].

What This Means for Your Care

Because these statistical associations exist, a new PG diagnosis will usually prompt your clinician to review your symptoms and medical history to guide an individualized evaluation ^[3].

It is important not to panic about the risk of “hidden” illnesses. There is no single universal screening panel or automatic cancer workup required for everyone with PG. Instead, you should simply continue your normal age-appropriate health and cancer screenings and report any new or unusual symptoms to your doctor.

Finally, while managing an associated condition can sometimes help with overall disease control, PG requires its own direct dermatologic treatments and wound care. Healing of the skin is not guaranteed simply by treating another illness, so direct care for your ulcers remains essential.