Case:
We present the case of a 45 year old right-handed lady who developed
chronic daily headache (CDH) with migraine features in 2018. She had
migraine headaches in her teens, often associated with her menstrual
cycle. The headaches progressively increased in frequency and severity
in her 30s. In January 2018, after a viral infection, she developed
unremitting headache with associated migraine symptoms and chronic daily
headache (CDH). The pain is usually holocranial. She also has bilateral
facial pain. There is associated phonophobia, worsening with physical
activity and severe fatigue. The patient denied photophobia, nausea,
vomiting and cranial autonomic symptoms. Poor sleep and physical
activity worsen the headaches. The clinical examination was normal,
including fundoscopy. Her routine blood tests including full blood
count, biochemical profile, renal, liver, thyroid function, vitamin B12
and folate were within the normal limits. MRI brain and MR venogram
(MRV) of the intracranial vessels were unremarkable. The patient has a
previous history of varicose vein surgery and panic attacks. Her other
medication consists of duloxetine 30mg daily, paracetamol PRN and
naproxen PRN.
A diagnosis of chronic daily headache (CDH) with migraine features was
made in 2018, and she was started on prophylactic medication. She had
failed four migraine prophylactic drugs due to side effects or lack of
efficacy: propranolol (minimal benefit), amitriptyline (weight gain),
topiramate (significant cognitive impairment) and venlafaxine (worsening
of headaches). Therefore, as per national and international guidelines,
she was started on erenumab 70mg, monthly subcutaneous injection. The
patient reported 40% improvement in headache severity and overall
migraine symptoms, but with no crystal clear days.
Two weeks after the second injection of erenumab, she developed
intermittent blue discoloration of both hands which worsened over a
period of 7-8 months on Erenumab treatment (see Figure 1). There was no
associated pain or sensory disturbance. The symptoms were worse in cold
weather and improved in the summer time. Hand movements also improved
the symptoms. The patient had never experienced such symptoms prior to
erenumab administration. A diagnosis of RP secondary to erenumab was
made. The patient initially declined discontinuation of erenumab, as she
feared worsening of headaches and associated symptoms. However, she
discontinued treatment after eight months due to the side effect of RP,
both voluntarily and on medical advice.