Pyoderma gangrenosum

# Overview
Pyoderma gangrenosum is a disease that causes tissue to become necrotic, causing deep ulcers that usually occur on the legs.  When they occur, they can lead to chronic wounds.  Ulcers usually initially look like small bug bites or papules, and they progress to larger ulcers.  Though the wounds rarely lead to death, they can cause pain and scarring.
The disease was identified in 1930.  It affects approximately 1 person in 100,000 in the population.  Though it can affect people of any age, it mostly affects people in their 40s and 50s.

# Types
There are two main types of pyoderma gangrenosum:
- the normal ulcerative form, which occurs in the legs
- an 'atypical' form that is more superficial and occurs in the hands and other parts of the body
Other variations are:
- Peristomal pyoderma gangrenosum is 15% of all cases of pyoderma
- Bullous pyoderma gangrenosum
- Pustular pyoderma gangrenosum
- Vegetative pyoderma gangrenosum

# Diagnosis

## Common Causes
Though the etiology is not well understood, the disease is thought to be due to immune system dysfunction, and particularly improper functioning of neutrophils.  At least half of all pyoderma gangrenosum patients also suffer from illnesses that affect their systemic function. For instance, ulcerative colitis, Crohn's disease,rheumatoid arthritis, myeloma sufferers have the condition.

## Physical Examination

### Extremities
- Pyoderma gangrenosum. Adapted from Dermatology Atlas.
- Pyoderma gangrenosum. Adapted from Dermatology Atlas.
- Pyoderma gangrenosum. Adapted from Dermatology Atlas.
- Pyoderma gangrenosum. Adapted from Dermatology Atlas.
- Pyoderma gangrenosum. Adapted from Dermatology Atlas.
- Pyoderma gangrenosum. Adapted from Dermatology Atlas.
- Pyoderma gangrenosum. Adapted from Dermatology Atlas.
- Pyoderma gangrenosum. Adapted from Dermatology Atlas.
- Pyoderma gangrenosum. Adapted from Dermatology Atlas.
- Pyoderma gangrenosum. Adapted from Dermatology Atlas.
- Pyoderma gangrenosum. Adapted from Dermatology Atlas.
- Pyoderma gangrenosum. Adapted from Dermatology Atlas.
- Pyoderma gangrenosum. Adapted from Dermatology Atlas.
- Pyoderma gangrenosum. Adapted from Dermatology Atlas.
- Pyoderma gangrenosum. Adapted from Dermatology Atlas.
- Pyoderma gangrenosum. Adapted from Dermatology Atlas.
- Pyoderma gangrenosum. Adapted from Dermatology Atlas.
- Pyoderma gangrenosum. Adapted from Dermatology Atlas.
- Pyoderma gangrenosum. Adapted from Dermatology Atlas.
- Pyoderma gangrenosum. Adapted from Dermatology Atlas.
- Pyoderma gangrenosum. Adapted from Dermatology Atlas.
- Pyoderma gangrenosum. Adapted from Dermatology Atlas.
- Pyoderma gangrenosum. Adapted from Dermatology Atlas.
- Pyoderma gangrenosum. Adapted from Dermatology Atlas.
- Pyoderma gangrenosum. Adapted from Dermatology Atlas.
- Pyoderma gangrenosum. Adapted from Dermatology Atlas.
- Pyoderma gangrenosum. Adapted from Dermatology Atlas.
- Pyoderma Gangrenosum
- Pyoderma Gangrenosum

# Associations
The common conditions associated with pyoderma gangrenosum are:
- Inflammatory bowel disease:
- Chronic ulcerative colitis
- Crohn's disease
- Arthritides:
- Rheumatoid arthritis
- Seronegative symmetrical polyarthritis
- Hematological disease:
- Myelocytic leukaemia
- Hairy cell leukaemia
- Myelofibrosis
- Myeloid metaplasia
- Monoclonal gammopathy (IgA) 

# Treatment
A number of treatment options exist.