^1,2Martin Lee

¹Mediclinic Parkview, Mohammed Bin Rashid University

Background:

Skin rashes are commonly an external visible marker of internal disease and are therefore often useful in the diagnosis of a variety of systemic diseases managed by rheumatologists. I present a case of a lady who developed 3 discrete episodes of different skin rashes over the course of 2 months that represented 3 different underlying pathologies but were nevertheless intrinsically linked.

Material(s) and Method(s):

A 42-year-old lady presented in October 2019 with a non-blanching, purpuric rash across her shins bilaterally. In September 2019, she returned from Thailand with mosquito bites on her arms and legs. Shortly after returning from Thailand, she presented to another hospital with fevers, myalgias and severe arthralgias. Her CRP was raised at 128 mg/l and she was given intravenous cefuroxime for 3 days followed by oral co-amoxiclav for presumed infected mosquito bites. Shortly after starting the intravenous cefuroxime, she developed a second rash on her torso, arms and legs. She was seen a week after discharge from hospital with ongoing severe arthralgias although her CRP had settled and was prescribed celecoxib 200 mg twice daily. Shortly after this, she developed a third rash on her shins bilaterally.

Results:

She presented in clinic in October 2019 with bilateral pedal oedema and a non-blanching, purpuric rash across her shins bilaterally consistent with Henoch Schonlein Purpura (HSP). A urinalysis was negative for blood and protein. She complained of widespread large and small joint polyarthralgias but this was no synovitis on examination. An anti-streptolysin O titer (ASOT) was negative but IgM and IgG antibodies to Chikungunya were positive. Her CRP was raised at 22 mg/l. A diagnosis of Chikungunya fever was made transmitted by mosquito bites followed by a maculopapular drug eruption secondary to cefuroxime and subsequent HSP secondary to recent infection. Her symptoms were treated with a reducing course of prednisolone 40 mg once a day and her rashes and arthralgias settled over the course of 2 months. Her urinalysis remained negative for blood and protein throughout.

Conclusion:

Chikungunya virus is an arthropod-borne virus that is transmitted by mosquito bites. It can cause fevers, severe polyarthralgias (70-100% of cases) and polyarthritis (44-63% of cases). Chronic arthritis has been reported in 25% to 75% of cases. Chikungunya fever is endemic in parts of Western Africa but is also common in many regions of Asia. Maculopapular drug eruptions are the most common type of drug hypersensitivity reaction and are characterized by a generalized eruption of erythematous macules or papules after initiating drug therapy. Maculopapular drug eruptions are common side effects of cephalosporins. The HSP is a small vessel leucocytoclastic vasculitis characterized by palpable purpura. The purpuric rash is typically symmetrical and located primarily in pressure dependent areas such as the lower extremities. Many cases of HSP are preceded by an upper respiratory tract infection such as Streptococcus but many other infectious agents have been implicated as possible triggers.