A rare case of hypokalaemic thyrotoxic periodic paralysis in a young African woman

Background: Thyrotoxic periodic paralysis (TPP) is a rare, potentially life-threatening complication of thyrotoxicosis, presenting with acute flaccid weakness and hypokalaemia. Typically presenting in young Asian males, TPP can affect all ethnicities. The diagnosis can be challenging in people with HIV (human immunodeficiency virus) on tenofovir disoproxil fumarate (TDF), where hypokalaemia may be misattributed to drug-induced renal potassium wasting.Case: A 31-year-old African woman on a TDF-based treatment regimen for HIV infection presented with acute generalised weakness and severe hypokalaemia (1.9 mmol/l ). Clinically she displayed subtle thyrotoxic symptoms, most notably loss of weight. Investigations showed suppressed TSH (0.005 mIU/l ) and elevated FT4 (32 pmol/l ). Low urinary potassium excluded TDF-related renal wasting. She was treated with intravenous potassium chloride, propranolol, and carbimazole, with rapid recovery. Thyroid scintigraphy confirmed toxic multinodular goitre, and she was referred for radioactive ablation.Discussion: TPP should be considered in patients with acute hypokalaemic paralysis, even without the classical features of hyperthyroidism. In high HIV-burden settings, distinguishing TPP from TDF-induced proximal tubulopathy is critical. Management includes correction of hypokalaemia, control of sympathetic symptoms, and definitive treatment of hyperthyroidism.Conclusion: This case highlights TPP as the initial manifestation of thyrotoxicosis in an African woman living with HIV on TDF-based ART. Awareness of this rare presentation is key for prompt diagnosis and timely management to prevent complications.