^{1, 2}Suad Hannawi, ³Maria Al-Salmi, ¹Haifa Hannawi

¹Al Kuwait-Dubai (Al Baraha) Hospital, Emirates Health Services (EHS), ²Ministry of Health and Prevention (MOHAP), ³Medical and Health Sciences, Sharjah University

Introduction: Hidradenitis suppurativa (HS) is a chronic, inflammatory skin disorder that affects apocrine units. Psoriasis is a chronic inflammatory disorder that prominently affects the skin and joints. Although the relationship between psoriasis and hidradenitis suppurativa has been reported in a number of case reports, yet, some evidence is controversial. A systemic review reported while a minority of patients had hidradenitis suppurativa before psoriasis, others suffered from paradoxical hidradenitis suppurativa following biological therapy used to treat psoriasis.

Method(s): We are presenting a case of PsO who developed HS after starting Adalimumab treatment

Result(s): MM is 30 years old Syrian patient with psoriasis for 7 years, on infliximab treatment.  seen for the first time by the rheumatology service when she was admitted to the medical ward of Al Kuwait-Dubai Hospital (Al Baraha) for severe flare-up of skin psoriasis (PsO) accompanied by the appearance of psoriatic arthritis (PsA) the first time, after stopping taking the PsO treatment (Infliximab) for 7 months, when she was in process of moving from Syria to the United Arab Emirates (UAE).

Physical examination proved the presence of multiple joint arthritis (involving elbows, proximal interphalangeal joints, knees, and ankles). The body was full of skin psoriasis. Infliximab had been resumed and the condition came under control with remission of PsO and PsA.

A few months after, MM was shifted to Adalimumab as part of the patient support program. 3 monthly assessments revealed a flare-up of PsO, Figure 1, 2, 3, and 4, and nail PsO. As well, there were areas of scars with depression at different places on the body. MM stated that since she started on Adalimumab, she had recurrent boils that required surgical excision. The boil excision was followed by an area of depression and scars at the place of excised boil (Figures 6 and 7). The diagnosis of the recurrent boils was an HS.

As a result of failure to Adalimumab, MM was shifted back to Infliximab. One week after the Adalimumab there was a complete clearance of the skin PsO (Figures 8 and 9). After 5 years of follow-up, PsO, and PsA were all in remission, with no recurrence of boils.

Conclusion(s): The cytokine profiles of HS, psoriasis, and anti-TNF-induced psoriasiform lesions are very similar. Therefore, like psoriasis, HS is a rare skin lesion that can develop while on anti-TNF therapy and is perhaps due to cytokine dysregulation as has been seen with TNF antagonists. The cytokine dysregulation that results in HS is class-specific (Adalimumab).