Atypical eruption but still Still's: case report and review of the literature

A Case of Multiple Necrotic Dyskeratotic Cells within the Upper Epidermis and Horny Layer Revealing Persistent Papules and Plaques of Adult-Onset Still's Disease

It is important to differentiate violaceous to dusky red papules and plaques that widely persist on the trunk and extremities because there are dermatoses that could be fatal, such as lupus erythematosus, dermatomyositis, drug eruptions, and graft-versus-host disease. Dyskeratotic cells only in the upper epidermis and horny layer are not well known, but it is a distinctive histopathological pattern of atypical type of rash of adult-onset Still's disease (AOSD). AOSD rash is a transient salmon-colored rash that occurs and disappears with fever; however, an atypical type of rash called "persistent dermal plaque" or "persistent pruritic eruptions" has also been reported. It occurs and persists even after fever subsides. Herein, we describe a case with necrotic dyskeratotic cells in the upper epidermis and horny layer without AOSD symptoms lasting for five years.

Histopathological diagnosis of persistent pruritic eruptions associated with adult-onset Still's disease

AIMS

Persistent pruritic eruptions (PPEs), presenting with dyskeratotic keratinocytes histologically, are characteristic skin rash in patients with adult-onset Still's disease (AOSD). The lesions may be histologically similar to other entities that present with dyskeratosis. In the present study, we compared the histopathological features between PPEs and other entities presenting with dyskeratosis.

METHODS AND RESULTS

To investigate whether histopathological findings can be used to discriminate among PPEs and other entities presenting with dyskeratotic keratinocytes, cutaneous histopathological changes of PPEs associated with AOSD (n = 26) were compared with those of systemic lupus erythematosus (SLE) (n = 16), dermatomyositis (n = 19), and drug eruption (n = 16). Dyskeratosis was observed in the upper one-third of the epidermal layer in all 26 PPEs. The rate of dyskeratosis for PPEs was higher than that for SLE (18.8%) and dermatomyositis (15.8%). In drug eruptions, the dyskeratotic cells were distributed in all levels of the epidermis. Variable densities of neutrophils were found in the dermis in all PPEs.

CONCLUSIONS

Although this was a retrospective study conducted at a single centre, presentation of dyskeratotic keratinocytes in the upper one-third of the epidermal layer is a distinctive histopathological reactive pattern of PPEs. This pattern may be a useful histopathological marker for early diagnosis of AOSD.

Adult-onset Still's disease with atypical cutaneous manifestations

The diagnosis of adult-onset Still's disease (AOSD) can be very difficult. There are no specific tests available, and diagnosis is usually based on a symptom complex and the well-described typical evanescent rash seen in the majority of patients. However, in recent years, other atypical cutaneous manifestations of AOSD have been reported. These atypical skin eruptions often present in addition to the typical evanescent rash but may also be the only skin manifestation, resulting in delayed diagnosis because of under-recognition.In this study, we present 3 new cases of AOSD with atypical cutaneous manifestations diagnosed during a 30-year period in our department and review 78 additional cases previously reported (PubMed 1990-2016). These 81 patients form the basis of the present analysis.The overall prevalence of atypical cutaneous manifestations in our AOSD population was 14%. These manifestations may appear at any time over the course of the disease, and usually occur in patients who have persistent and severe disease, with a considerable frequency of clinical complications (23%), including serositis, myopericarditis, lung involvement, abdominal pain, neurologic involvement, and reactive hemophagocytic syndrome.The most representative and frequent lesion among the nonclassical skin rashes is the development of persistent pruritic papules and/or plaques. Interestingly, these lesions show a distinctive histological pattern. Other, less frequently observed lesions include urticaria and urticaria-like eruptions, generalized or widespread non-pruritic persistent erythema, vesiculopustular eruptions, a widespread peau d'orange appearance of the skin, and edema of the eyelids mimicking dermatomyositis without any accompanying skin lesion.The great majority of these patients required medium or high doses of glucocorticoids (including intravenous methylprednisolone pulse therapy in some cases) and, in nearly 40%, a more potent or maintenance immunotherapy with immunosuppressant drugs and/or biologic agents (mainly anakinra or tocilizumab) to control or manage symptoms because of a polycyclic or chronic course. The development of atypical cutaneous manifestations seems to be associated with a potentially worse prognosis, with a mortality rate reaching 8% primarily because of infectious complications related to immunosuppressive therapy.In conclusion, the appearance of atypical cutaneous manifestations is not uncommon in AOSD. Recognition of this clinical variant is crucial for the early diagnosis of AOSD, as it might imply persistent disease activity and the need for more aggressive treatment.