PAPA Syndrome

PAPA (pyogenic arthritis, pyoderma gangrenosum, and acne) syndrome is a rare, inherited, early-onset autoinflammatory disease characterized by recurrent pyogenic arthritis, pyoderma gangrenosum, and acne.


Epidemiology:

PAPA syndrome is a rare disease, with fewer than 50 cases reported worldwide. The disease presents in childhood or adolescence, although adult-onset cases have also been reported. It is an autosomal dominant disease, which means that if one parent has the mutation, there is a 50% chance that the child will inherit it.


Etiopathogenesis:

PAPA syndrome is due to mutations in the PSTPIP1 gene, which encodes for the protein PEST and Poxvirus Intermediate Protein Domain Structure Assembly-1. This protein is involved in the regulation of inflammation and immune response.


Symptoms:

PAPA syndrome is characterized by the occurrence of recurrent pyogenic arthritis, pyoderma gangrenosum and acne. Pyogenic arthritis presents as recurrent joint pain and inflammation, which can lead to joint destruction if not adequately treated. Pyoderma gangrenosum is a painful skin lesion that can appear anywhere on the body, but is mainly located on the skin of the leg. Acne can be very severe and resistant to treatment.


Diagnosis:

The diagnosis of PAPA syndrome is based on the presence of the three main symptoms: pyogenic arthritis, pyoderma gangrenosum and acne. Genetic testing can also help to confirm the diagnosis.


Treatment:

There is no curative treatment for PAPA syndrome, but symptoms can be treated to improve the patient's quality of life. Treatment of pyogenic arthritis is based on the administration of non-steroidal anti-inflammatory drugs (NSAIDs), corticosteroids and, in some cases, disease-modifying drugs (DMARDs) such as methotrexate. Pyoderma gangrenosum is treated with anti-inflammatory drugs and antibiotics. Acne is treated with topical and systemic therapies, including antibiotics and retinoids. Biologic therapy with anti-IL-1 or anti-IL-6 agents has been used successfully in some cases.