Persisting fatigue and myalgia as the presenting features in a case of hypokalaemic periodic paralysis

Abstract

We report a case of a 9-year-old boy who developed hypokalaemic periodic paralysis (HypoPP) following a prodrome of persistent fatigue and muscle aches associated with mildly elevated creatine kinase (CK) levels. HypoPP is usually associated with a sudden onset of weakness and hypokalaemia at presentation. A review of published cases failed to identify any other reports of individuals with a similar onset of symptoms and elevated CK levels prior to the development of frank HypoPP. In the case described above, the association of these symptoms with elevated levels of CK may have been related to the underlying mutation in the skeletal muscle calcium channels that was subsequently identified. In cases of persisting fatigue and myalgia associated with elevated CK levels it may be helpful to consider HypoPP in the differential diagnosis.