A 71-year-old woman with remitting multi-resistant tender papules with a metameric disposition was initially treated as herpes zoster. She later developed a chronic ulcer on the scalp that, after investigation, was indicative of pyoderma gangrenosum (PG) or pyoderma-like. She had a previous history of pulmonary tuberculosis and PG on both legs in 2003. She was treated with cyclosporine, infliximab, clofazimine, doxycycline, and intralesional triamcinolone injections with varying results for over four years. PG was finally controlled in mid-2007. She remained asymptomatic until March 2020, when intense and sudden pain on the vertex and left parietal region developed. Multiple tender papules with peripheral erythema were present. Although no vesicles were found, a tentative diagnosis of cephalic herpes zoster was suspected. Despite treatment with valacyclovir and pregabalin, symptoms increased, and papules evolved into multiple, deep, ulcerated lesions with a central necrotic scab and undermining border. Expression yielded a significant amount of purulent secretion. Skin biopsy findings were of an ulcer with exuberant granulation tissue. Histology study was performed on the material obtained while curetting one of the large abscesses rather than by a wedge excision of the border. Although the vertex aspect on the scalp suggested an erosive pustular dermatosis of the scalp, histology was more consistent with PG. Attempts to obtain microbiological cultures were twice negative.
Previous comorbidities include IgA multiple myeloma in remission for the past seven years and remission of pulmonary tuberculosis treated with triple therapy 18 years ago. In the process of choosing a proper therapy, the Quantiferon test was performed, which was negative. After a short period of use of oral Dapsone, the disease progressed. Due to the previous history of tuberculosis and possible contra-indications for anti-TNF alpha therapy, she was started on baricitinib, a novel Janus kinase (JAK) inhibitor, 4 mg orally daily, taking into consideration the past attempts with more conservative approaches mentioned above. The idea of using JAK inhibitors was considered in the case of failed treatments, which proved helpful. Lesions started to improve, and by seven days, no new lesions were identified. Complete regression was achieved after five weeks, leaving a depressed scar (Fig. 1, Fig. 2).
Case 2 A 59-year-old female with rheumatoid arthritis since 2011, controlled with methotrexate 15 mg/week, developed in 2018 a leg skin ulcer for which PG was diagnosed. Healing was obtained with dressings and MTX maintenance.
In 2019, another PG occurred on the left leg and ankle; treatment consisted of prednisone 0.7 mg/kg/d associated with MTX 20 mg/week. PG resolved in 4 months; corticotherapy was gradually tapered, and MTX was maintained. Severe Cushing's syndrome signs were noted, impairing quality of life.
In 2020, another outbreak of PG compromised the right leg; methotrexate was suspended, and baricitinib 4 mg/day was introduced, with the lesion's healing in 3 months presented in the photos (Fig. 3, Fig. 4).