Secondary hyperhidrosis is the topic du semaine this time. When patients tell me they’re having heavy sweats I sigh that inward sigh that comes from having no real idea what I’m doing, happily attribute it to menopause if age and gender happen to permit, and otherwise check their lymph nodes, FBC, plasma viscosity and TFTs. So what am I missing?
Well, the differential diagnoses include:
Infective: TB, endocarditis, and HIV are the examples mentioned. So think chest, heart, and T-cells.
Endocrine: Menopause and thyrotoxicosis I already knew. (Two quick points on menopause – don’t assume that that’s the cause just because the patient is a woman of the right age, and don’t assume that it’s not the cause just because the patient is a woman somewhat past the right age, as patients can present with menopausal symptoms ‘some time’ [unspecified] after completing the menopause.) Diabetes I didn’t know and probably should. The zebras include phaeochromocytoma, acromegaly, and carcinoid syndrome.
Neurological: Parkinsonism surprised me as a possible cause. Neuropathies are also mentioned but not specified, which was less helpful.
Malignancies: Lymphomas and myeloproliferative disorders, so I suppose I’d have thought of those.
Medication: SSRIs (rather ironic, since they can actually improve hot sweats in the menopause, I recall from elsewhere), venlafaxine and tricyclics. Tamoxifen and GnRH agonists, logically enough. And aspirin and NSAIDs, less logically.
Alcohol/drug withdrawal: One for the ‘should have known that but didn’t think of it’ column.
So, what should I be covering that I’m not? With regard to history, the article just says rather unhelpfully that ‘a full medical history should be taken’, but I suppose it follows from the above that I should ask about cough, weight loss, fever, a history of heart valve problems/childhood rheumatic fever, polyuria/polydipsia, symptoms of thyrotoxicosis, periods, problems with gait/movement, medication list, and history of alcohol/drug use, including injection of anything illicit.
Examination – check lymph nodes, heart, chest, liver/spleen, tremor/thyroid size.
Bloods – think I had it covered, but, on the subject of investigations, remember CXR is likely to be helpful. Consider carcinoid and possible 24-hour urinary excretion of 5HIAA. And, if in doubt, refer to an endocrinologist for investigation of possible rare causes.