Hyperhidrosis is a condition in which an individual sweats excessively and has major impacts on social life. It affects 1-3% of the US population, with most cases aged 25 to 64.
It has been shown that this excessive production affects social lives due to odor and appearance issues such as dampness, underarms, stains on clothes, resulting in embarrassment and anxiety. It can have major psychosocial repercussions for patients because sweating affects the ability to be comfortable in social situations and other parts of life.
There are two types: primary Focal hyperhidrosis (without a specific condition) and secondary hyperhidrosis (associated with an underlying medical condition).
Therefore, doctors typically suggest working up to every possibility to rule out other pathologies that may cause excessive sweating on different parts of our body beyond one’s underarms and palms. Sweating is most often focal (in a specific area), causing idiopathic symmetrically-bilateral sweaty armpits, hands/palms, feet/soles, and the craniofacial region, which includes forehead or scalp areas, for example.
Several other conditions may be attributed to secondary hyperhidrosis, such as drugs, endocrine disturbances, obesity, hypoglycemia, heart failure, certain malignancies and central nervous system abnormalities.
Individuals with hyperhidrosis can be distinguished depending on the distribution of their affected regions (focal or generalized) and whether they experience excessive sweating on one side or both sides.
Primary Focal Hyperhidrosis
Primary hyperhidrosis is a condition where the autonomic system becomes unbalanced, leading to excessive sweating. It is more often focal and occurs in areas with higher eccrine glands such as palms, soles, axillae. The uncommon cases that affect the forearm or forehead on one side only documented are rare; family history suggests this disorder might be hereditary.
Hyperhidrosis of the hands, feet and underarms may be due to abnormal central control of emotional sweating. They similarly affect these areas when we experience emotions like fear or anxiety.
The histologic evaluation of the affected areas demonstrated normal-appearing eccrine sweat glands with an average number, size, and density. The most plausible theory is that stimuli would usually increase sweating (stress or hot temperature) cause hyperactivity in eccrine sweat glands because this mechanism does not involve apocrine gland activity.
A survey conducted on 150,000 American households indicated that the prevalence of hyperhidrosis was 2.8% or 7 million Americans, and around 38 % consulted their doctor about it. The authors believe this means more people are affected by excessive sweating than previously thought.
Primary hyperhidrosis is a condition where we sweat excessively. It is usually seen during childhood and peaks in the third and fourth decade but can be seen even earlier. In one survey, it was found that people started to experience this problem at an average age of 25 years old, with rates being highest between 25-65 years (3.5–4.5 %). The lowest prevalence rate observed was less than 12 years of age (0.5–0.7%). According to other surveys done on patients suffering from different forms of primary hyperhidrosis, there are significant differences too!
Of all the hyperhidrosis patients, 51% have axillary hyperhidrosis alone or in combination with another area. This is followed by palmar and plantar hyperhidrosis at 9.5 % each, and 25 % have palmar hyperhidrosis alone or in combination with hyperhidrosis in another area, and only 1 % have palmar hyperhidrosis alone.
Secondary generalized hyperhidrosis is excessive sweating caused by a medical condition or medication. Underlying conditions that may cause secondary hyperhidrosis can be physiologic, such as pregnancy, menopause, fever, heat exposure, or pathologic including malignancies (cancer), carcinoid syndrome (neuroendocrine tumor of the GI tract), hyperthyroidism, pheochromocytoma, tuberculosis, endocarditis, HIV, among others.
Drugs that may cause hyperhidrosis include antidepressants, hypoglycemic agents, triptans (drugs used to treat migraine), antipyretics (medications for fever reduction) and cholinergic drugs. It is worth noting that it also occurs as a clinical feature of social anxiety disorder. Peripheral nerve injury can sometimes lead to secondary focal hyperhidrosis too.
Patients with secondary hyperhidrosis tend to be older than those with primary types of this condition. Other factors that differentiate between the two include onset and symptoms associated with sweating.
Patients with primary hyperhidrosis are much more likely to experience sweating in typical distribution; however, those with secondary hyperhidrosis often exhibit unilateral or asymmetrical sweating. In addition, they tend to be generalized rather than focal and can also suffer from night sweats (sweating during sleep). Secondary hyperhidrosis is less often associated with positive family history. A middle-aged patient presenting with new-onset generalized or asymmetrical sweating while sleeping is highly suspicious for secondary hyperhidrosis.