Erysipelas-like erythema with familial Mediterranean fever

Skin rash and arthritis a simplified appraisal of less common associations

Skin and joint manifestations are part of the clinical spectrum of many disorders. Well-known associations include psoriatic arthritis and arthritis associated with autoimmune connective tissue diseases. This review focuses on less common associations where skin lesions can provide easily accessible and valuable diagnostic clues, and directly lead to the specific diagnosis or limit the list of possibilities. This may also affect health care resources as diagnostic tests are often low-specific, highly expensive and poorly available. This group of diseases can be divided into two subsets, based on the presence/absence of fever, and then further classified according to elementary skin lesions (macular, urticarial, maculo-papular, vesico-bullous, pustular, petechial and nodular). In most instances joint involvement occurs as peripheral migrating polyarthritis. Erythematosus macular or urticarial rashes occur in most febrile disorders such as monogenic autoinflammatory syndromes, Schnitzler's syndrome, Still's disease and rheumatic fever and afebrile diseases as urticarial vasculitis. Pustular rash may be observed in chronic recurrent multifocal osteomyelitis (CRMO) and pyogenic arthritis with pyoderma gangrenosum and acne (PAPA) syndrome (both febrile) as well as in Behcet's disease and Synovitis, acne, pustulosis, hyperostosis and osteitis syndrome (both non-febrile). Papular lesions are typical of secondary syphilis, sarcoidosis, interstitial granulomatous dermatitis, papular petechial of cutaneous small-vessel vasculitis and nodular lesions of polyarteritis nodosa and multicentric reticulohistiocytosis all of which are afebrile. Differential diagnosis includes infections and drug reactions which may mimic several of these conditions. To biopsy the right skin lesion at the right time it is essential to obtain relevant histological information.

Erysipelas-like erythema of familial Mediterranean fever syndrome: a case report with emphasis on histopathologic diagnostic clues

We report histopathological findings in a case of familial Mediterranean fever (FMF) syndrome with an erysipelas-like erythema (ELE). ELE is the only pathognomic cutaneous manifestation of FMF. ELE is characterized by well-demarcated, tender, erythematous and infiltrated plaques recurring on the same site and resolving spontaneously within 48-72 h. FMF is a monogenic autoinflammatory syndrome highlighted by recurrent fever associated with polyserositis involving mainly the peritoneum, synovium and pleura. FMF results from a mutation of the MEFV gene, which encodes for pyrin, leading to Il-1β activation and promoting neutrophil migration into the dermis. Histopathological findings in our case showed a sparse superficial perivascular and interstitial lymphocytic infiltrate admixed with some neutrophils, no eosinophils and mild papillary dermal edema. Venules and lymphatics were dilated, though no vasculitis was identified. Neutrophils are the most common cutaneous marker of autoinflammation, and cutaneous manifestations of monogenic autoinflammatory syndromes are represented by the spectrum of aseptic neutrophilic dermatoses. Neutrophils in the presence of recurrent fever and in the correct clinical context of recurrent erysipelas in the same site are a diagnostic clue for FMF.

Autoinflammation: From monogenic syndromes to common skin diseases

Autoinflammation is characterized by aberrant regulation of the innate immune system and often manifests as periodic fevers and systemic inflammation involving multiple organs, including the skin. Mutations leading to abnormal behavior or activity of the interleukin 1 beta (IL-1ß)-processing inflammasome complex have been found in several rare autoinflammatory syndromes, for which anticytokine therapy such as IL-1 or tumor necrosis factor-alfa inhibition may be effective. It is becoming clear that features of autoinflammation also affect common dermatoses, some of which were previously thought to be solely autoimmune in origin (eg, vitiligo, systemic lupus erythematosus). Recognizing the pathogenetic role of autoinflammation can open up new avenues for the targeted treatment of complex, inflammatory dermatoses.