Discussion
Dermatological complications in RA patients can be specific or related to skin disease due to the treatment taken by a patient (11). RA specific skin lesions are seen only in RA patients and include accelerated rheumatoid nodules, rheumatoid vasculitis, rheumatoid nodules and RND (8). Rheumatoid arthritis-related skin diseases include dermatoses that are associated with RA (12, 13). This group of skin disorders includes pyoderma gangrenosum, sweet’s syndrome, Raynaud’s phenomenon and erythema elevatum diutinum (EED). RND was first described by Ackerman in the last century. It is a rare and distinct manifestation of RA with high frequencies in females compared to males; only less than 20 cases had been described until now (14, 15).
The prevalence of RND is less than 2% among all RA patients (16). The exact pathophysiology of the condition is unknown; however, it is believed to be an immune-complex-mediated disease (17). RND commonly appears in patients with severe, chronic seropositive arthritis and clinically manifests as asymptomatic nodules, erythematous papules and urticaria-like lesions (7, 8). The dermatological lesion in RND can be either palpable purpura, or plaque or nodule in the Extensor surfaces of extremities and joints are favoured locations as in our presenting patient who showed nodulopapular lesions in the thighs and the lower part of the abdomen (7, 18). The differential diagnosis was considered and ruled out, which includes dermatitis herpetiformis ruled out by the absence of bullous lesions, A drug eruption was also ruled out because the lesions persisted and worsened in spite of cessation of medications, sweet syndrome was also excluded as the patient was not on any of the medications that can cause a Sweet’s-like drug hypersensitivity (19). Behcet’s disease, bowel-associated dermatosis arthritis syndrome and pyoderma gangrenosum were ruled Out by history and absence of ulcerative or vesiculopustular lesions. Erythema elevatum diutinum was ruled out by the absence of vasculitis (20).