Recurrent multiple cutaneous aseptic abscesses with spontaneous regression: An unusual case report
Aseptic abscess (AA) is a rare disease featuring sterile nodules consisting of neutrophilic infiltration, which is frequently associated with other systemic symptoms/diseases and requires systemic therapy for remission.1 However, cases of AA with spontaneous regression have not been reported. Here, we report a case of recurrent multiple cutaneous AA with spontaneous regression.
A 19‐year‐old woman presented with a 4‐month history of gradually enlarging multiple nodules on her upper extremities (Figure 1a,b). Her medical history was unremarkable and she had no other findings such as fever or uveitis. Routine blood tests, including white blood cell counts and C‐reactive protein, were normal and positron emission tomography/computed tomography revealed no other lesions except for the nodules. Human leukocyte antigen (HLA) typing revealed HLA‐A2/24, HLA‐B46/59 and HLA‐Cw1. Histologically, the resected right forearm nodule revealed a nodular lesion in the deep dermis, consisting of dense neutrophilic infiltration and focal necrosis with surrounding granulomatous reaction composed of histiocytes, lymphocytes and plasma cells (Figure 1d–f). Tissue cultures and mycobacterial polymerase chain reaction (PCR) were both negative. PCR for T‐ and B‐gene rearrangements revealed a polyclonal pattern. The biopsied left forearm nodule also showed similar histological findings. From these findings, AA was diagnosed. Within 6 months of the biopsy, all remaining nodules had gradually diminished then completely regressed (Figure 1g). However, a new nodule recurred on the right upper arm 13 months after the biopsy. Although this nodule also spontaneously regressed, three nodules again appeared on the forearms 20 months after the initial biopsy. The biopsied left forearm nodule also revealed similar histological findings (Figure 1h–j). As of 6 months of follow up after the second biopsy, the remaining nodules have regressed and no recurrence has been observed.
Although AA typically involves intra‐abdominal organs, extra‐abdominal organs such as the brain, lungs and skin may also be involved1. However, only a few cases of cutaneous involvement alone as in our case have been reported.1, 2 AA frequently occurs along with systemic symptoms such as fever and may be associated with other systemic diseases including inflammatory bowel disease.2 Although AA histology is characterized by neutrophilic infiltration with surrounding granulomatous reaction, persistent inflammation from various disorders could lead to granulomatous reaction.3, 4 Additionally, our case shows HLA‐Cw1, which is associated with Sweet’s disease (SD), especially with neurological involvement.5 Therefore, given the isolated cutaneous involvement, the pathogenesis of our case may be close to SD, which would also show cutaneous neutrophilic infiltration, although the diagnosis of AA was made based on histological findings of abscesses surrounded by granulomatous reaction in all examined nodules.
Steroid therapy is typically required for remission of AA.1 In contrast, all of the lesions in our case spontaneously regressed, which has not been previously reported. Additionally, our case showed isolated cutaneous involvement, suggesting a non‐aggressive form. However, AA sometimes precedes development of systemic diseases and cases involving other organs or development of systemic diseases appearing several years after AA diagnosis have been reported.1 Moreover, given that our case has HLA‐Cw1, significantly associated with neuro‐SD, long‐term follow up, including neurological as well as intestinal examinations, is necessary.
ACKNOWLEDGMENT
We thank Dr Bryan J. Mathis of the University of Tsukuba Medical English Communications Center for English‐language editing of this manuscript.
CONFLICT OF INTEREST
None declared.
