Pyoderma gangrenosum (PG) is a rare neutrophilic dermatosis characterized by rapidly developing and painful skin ulcers with distinctive features. As far as we are concerned, there is no previous case report on facial PG in East-Asia. In this case, we describe a case of a 79-year-old man with a 3-month history of progressive painful ulcers on his cheek and upper lip. Initial suspicion of atypical mycobacterium infection led to an ineffective treatment regimen. Comprehensive infectious testing yielded negative results, and a positive pathergy test indicated a potential diagnosis of PG. A skin biopsy confirmed the diagnosis, and the patient showed significant improvement with intravenous methylprednisolone and oral cyclosporine treatment. After three months, complete resolution of the lesions was achieved without recurrence. The case highlights the diagnostic challenges associated with PG, which is often misdiagnosed due to its resemblance to other conditions. Thorough evaluation is crucial to exclude alternative diagnoses, particularly cutaneous infections. Clinical morphology, tissue biopsy, and culture are essential for accurate diagnosis. The presence of pathergy, the development of new lesions following minor trauma, can also be a diagnostic clue.

Sweet syndrome is a rare complication of azathioprine treatment with unelucidated clinical features. The purpose of this study was to investigate the clinical characteristics of azathioprine-induced Sweet syndrome (AISS) and provide a reference for diagnosis, treatment and prognosis. We collected relevant case reports of AISS by searching Chinese and English databases from 1960 to December 31, 2022, extracted the data and carried out a retrospective analysis. The median age of the 44 patients was 50 (range 9-89) years, and they included 32 males (72.7%). Fever (86.4%) and arthralgia (31.8%) were the most common clinical symptoms. The skin lesions were mainly pustules (54.5%), papules (40.9%), plaques (40.9%) and nodules (31.8%), which were mainly distributed on the extremities (54.5%), face (38.6%) and hands (36.4%). Laboratory examination revealed neutropenia (65.9%) as well as elevated C-reactive protein (63.6%) and erythrocyte sedimentation (40.9%) rates. Histopathology of the lesioned skin showed neutrophil infiltration (93.2%) and dermal edema (38.6%). Symptom relief was achieved at a median time of 7 days (range 2-28 days) after azathioprine discontinuation in all patients. Nine patients (20.5%) had skin lesions that recurred within 24 h after taking azathioprine again. Clinicians and pharmacists should grasp the regularity and characteristics of AISS and should not recommend the readministration of azathioprine, to avoid the recurrence of Sweet syndrome.

Autoinflammatory diseases (AIDs) are a heterogeneous group of disorders in which recurrent or continuous aseptic inflammation arises primarily through antigen-independent hyperactivation of the innate immune system. The skin is frequently involved with a wide variety of cutaneous manifestations, most of which are non-specific. Recognition of skin lesions in AIDs may sometimes provide clues for a correct diagnosis. In this review, the cutaneous involvements of >20 selected AIDs were summarized and organized into different categories based on their characteristic manifestations, such as urticarial dermatosis, neutrophilic dermatosis, granulomatosis, chilblain, lipodystrophy, and hyperkeratosis. With this classification scheme, cutaneous manifestations in AIDs could be more easily identified to facilitate diagnosis in clinical practice.

Pyoderma gangrenosum (PG) is a rare chronic neutrophilic dermatosis that causes undermining ulcers. Unfortunately, standardization of PG treatment remains a challenge. In this article, we describe a case in which a 69-year-old man presented with a painful ulcer on the right lower leg. The diagnosis of PG was made after excluding other diseases. He had a history of PG on his left lower leg 2 years earlier and was cured by the treatment of systemic corticosteroids and cyclosporin A for 43 days. However, such a treatment was not effective this time. Hence, we applied intravenous immunoglobulin and negative-pressure wound therapy, and the patient was cured. Altogether, this case supports the use of intravenous immunoglobulin as an effective adjuvant for refractory PG, and indicates negative-pressure wound therapy as a treatment option to advance ulcer healing under adequate immunosuppression.

BACKGROUND: We report a rare case of chronic brucellosis accompanied with myelodysplastic syndrome and neutrophilic dermatosis, which to the best of our knowledge, has never been reported.
METHODS: A young man was admitted to our hospital complaining of recurrent fever, arthritis, rashes and anemia. He had been diagnosed with brucellosis 6 years prior and treated with multiple courses of antibiotics. He was diagnosed with myelodysplastic syndrome and neutrophilic dermatosis following bone marrow puncture and skin biopsy. After anti-brucellosis treatment and glucocorticoid therapy, the symptoms improved.
CONCLUSIONS: Clinicians should consider noninfectious diseases when a patient who has been diagnosed with an infectious disease exhibits changing symptoms.