Discussion:
EGPA which is also called as Churg-Strauss syndrome, an ANCA related
small vessel vasculitis presenting with a three-phase progressive course
of the following, a prodromal allergic phase of asthma and
rhinosinusitis, then eosinophilic inflammatory infiltrates develop in
the tissues and lastly a vasculitic phase such as purpura and
mononeuritis multiplex. Pathophysiology of the latter is caused by
axonal degeneration of the nerves due to ischemia caused by the
vasculitis itself.
Mononeuritis multiplex as well as peripheral neuropathy are a common
presentation in patient diagnosed with EGPA, in a large published series
about 50-60% suffered from peripheral neuropathy and mononeuritis
multiplex was slightly more common than peripheral neuropathy, with
lower limbs being the most affected 2,3 with the
peroneal, tibial, ulnar, and median nerves; being the most common nerves
to be attacked, furthermore complicated by asymmetric foot or wrist
drop, also can potentially evolve into symmetric or asymmetric
polyneuropathy; sensory deficits and neuropathic pain4,5 as was seen in our patient.
Although this neuropathic involvement is less likely to be detrimental
compared to lung and renal involvement, it does markedly affect the
patient’s quality of life. Our patient presented with paraesthesia which
then progressed to weakness of all four limbs and right wrist drop and
bilateral foot drop in a non-characteristic manner of GBS associated
with severe neuropathic pain, with notable eosinophilia and a history of
asthma, with no other organ involvement.
EGPA should always be in the differentials when thinking of treating or
diagnosing a patient with GBS as the treatment differ and may cause life
threatening complications. Accurately diagnosing EGPA is imperative due
to the known treatment delay related progression into irreversible organ
dysfunction.
Management of EGPA initially requires the use of high dose systemic
steroids with the aim to achieve and maintain clinical remission
swiftly. Second line, in cases that do not respond to steroids, other
immunosuppressants like cyclophosphamide are needed. Other promising
treatment options are biologic agents like anti-interleukin-5
mepolizumab, which was used in our patient. Prognosis of untreated EGPA
is very poor. Reported as a 5-year survival of 25%. Whereas when
diagnosed quickly and treated appropriately, prognosis is much improved,
with study findings of 78-month survival rate at about 70-90%6.