Skin rash and heart palpitations: what to know

Palpitations feel like pounding, fluttering, skipped beats or a fast heartbeat. A rash may be raised, flat, itchy, blistered or widespread. Heat, anxiety, fever, dehydration, low blood sugar and some medicines can produce overlapping symptoms. Anaemia and iron deficiency anaemia can make the heart beat faster as the body carries less oxygen. Hyperthyroidism can cause a racing heart with warmth, sweating or tremor. Atrial fibrillation may feel irregular rather than simply fast. A rash with sudden swelling, wheezing, throat tightness or faintness can signal a severe allergic reaction.

Stop strenuous activity and sit somewhere cool. Note when each symptom began, whether the heartbeat is regular, what the rash looks like, and any new food, medicine, supplement or product. Sip fluids if you can drink normally. Do not start, stop or reuse prescription medicine without advice. Arrange prompt medical review if the symptoms are new, recurring or persistent; a clinician may check your pulse, skin, blood tests and an electrocardiogram.

Call emergency services for trouble breathing, swelling of the lips or tongue, chest pain, fainting, severe weakness, confusion, or a heartbeat that remains very fast or irregular with feeling unwell. Seek same-day care for a rapidly spreading rash, fever with a rash, or palpitations that continue at rest. Do not drive yourself if you feel faint or short of breath.

Could the rash and palpitations share a cause, or are they separate? Which medicines, foods or products should I avoid? Do I need an ECG, blood count, thyroid test or glucose check? What symptoms should prompt emergency help?