** Acne fulminans
This emergency affects adolescent boys who have previously had mild to moderate acne.
Haemorrhagic, crusted, ulcerative skin lesions erupt on the back, chest, arms, and face.
Systemic symptoms include fever, malaise, weight loss, myalgia, and arthralgia. Patients
may have hepatosplenomegaly or erythema nodosum.
Radiographs show lytic bone lesions, most often affecting the sternum and clavicle, but
osteolytic lesions have been seen in the hips, ankles, and humerus. Osteolytic lesions are
sterile. Sternoclavicular hyperostosis and sacroiliitis have also been described. Periosteal
formation of new bone, sclerosis, and thickening occur late. Bony changes are transient,
and the prognosis is good. Findings may be consistent with SAPHO syndrome.
** Acne conglobata
Seronegative spondyloarthropathy and SAPHO syndrome have also been described in
patients with acne conglobata.
** What is SAPHO syndrome?
SAPHO syndrome, an auto-inflammatory bone disease, may account for 4% of all
patients with seronegative spondyloarthropathies. Inflammatory bowel disease is
associated with SAPHO.
** The syndrome is characterized by:
• Intermittent predominantly axial Synovitis (sternum, clavicles, ribs, spine, pelvis).
• Aseptic Osteitis and Hyperostosis. Bony pain is common.
• Ct scans show lytic bone lesions—these are sterile.
• Chronic (or relapsing) sterile pustular Acneiform eruptions or palmoplantar Pustulosis.
• Leucocytosis and anaemia.
Treatment is unsatisfactory. Tetracycline antibiotics or isotretinoin may control acne.
Topical steroids and acitretin may control palmoplantar pustulosis. NSAIDs,
prednisolone, and methotrexate have been used for synovitis. Infliximab (anti-TNF) and
bisphosphonates (suppress osteoclasts) have also been recommended.
PAPA syndrome.
Very rare AD auto-inflammatory syndrome caused by mutations in PSTPIP1/CD2BP1
gene encoding a protein that interacts with pyrin. PAPA, like FMF, is associated with
decreased apoptosis and high levels of IL-1B. Patients have severe destructive sterile
arthritis (often precipitated by minor trauma), as well as scarring cystic acne, sterile
abscesses (often at injection sites), and PG-like ulcers. Treatments include
corticosteroids, etanercept, infliximab, and anakinra.
Also see PASH (Pyoderma gangrenosum, Acne, Suppurative hidradenitis)—another very
rare auto-inflammatory syndrome.