How is hyperhidrosis diagnosed?

The cause of the hyperhidrosis: first determine the type of hyperhidrosis

The diag­no­sis of pri­ma­ry, focal hyper­hidro­sis is based on inter­views with affect­ed patients, clin­i­cal find­ings, and fur­ther tests as nec­es­sary.

In the fol­low­ing, we would like to explain how the cause of the hyper­hidro­sis is diag­nosed based on the guide­lines for the def­i­n­i­tion and treat­ment of pri­ma­ry hyper­hidro­sis set by the Ger­man Der­ma­to­log­i­cal Soci­ety (as of 1 Novem­ber 2017).

The cause of sec­ondary hyper­hidro­sis is usu­al­ly an under­ly­ing dis­ease.
There­fore, the focus should be on the diag­no­sis and treat­ment of the under­ly­ing dis­ease; this is why we don’t address sec­ondary hyper­hidro­sis here.

Typical signs of primary, focal hyperhidrosis

Patient inter­view (med­ical his­to­ry): Dur­ing the con­ver­sa­tion with your treat­ing physi­cian, they will ask you some ques­tions about your strong sweat­ing.

The fol­low­ing are typ­i­cal indi­ca­tions of pri­ma­ry (focal) hyper­hidro­sis:

  • onset of symp­toms in child­hood, ado­les­cence, or ear­ly adult­hood (usu­al­ly by age 25; with hand symp­toms usu­al­ly occur­ring before puber­ty)
  • sweat­ing regard­less of tem­per­a­ture, unpre­dictable, and not will­ing­ly con­trol­lable
  • local­ized occur­rence in one or more sites prone to a dis­ease with bilat­er­al, sym­met­ric involve­ment
  • occurs more than once a week and impairs the qual­i­ty of every­day life
  • no increased sweat­ing dur­ing sleep
  • pos­i­tive fam­i­ly his­to­ry

Pri­ma­ry focal hyper­hidro­sis is a dis­ease with no known cause. If the med­ical his­to­ry indi­cates this diag­no­sis, there is no need for rou­tine lab­o­ra­to­ry or imag­ing. The diag­no­sis is based pri­mar­i­ly on the inter­view and clin­i­cal find­ings.

Determine the severity of the hyperhidrosis

As part of the clin­i­cal find­ings, your hyper­hidro­sis can be clas­si­fied in terms of sever­i­ty:

Level 1 (mild hyperhidrosis):

The armpits and/or hands and feet show a sig­nif­i­cant­ly increased skin mois­ture. If the armpits are affect­ed, sweat spots 5 to 10 cm in diam­e­ter are com­mon.

Level 2 (moderate hyperhidrosis):

Beads of sweat form on the under­arms and/or hands and feet. With hyper­hidro­sis of the hands or feet, the sweat­ing is still lim­it­ed to the soles of the feet or the palms of the hands. If the armpits are affect­ed, sweat spots 10 to 20 cm in diam­e­ter are com­mon.

Level 3 (severe hyperhidrosis):

The sweat drips down from the under­arms and/or hands and feet. If the hands and/or feet are affect­ed, there will be sweat on the fin­gers and toes and on the sides of the hands and feet. If the armpits are affect­ed, there are sweat spots with diam­e­ters over 20 cm.

In addi­tion to the inter­view and clin­i­cal clas­si­fi­ca­tion, the restric­tions on the qual­i­ty of life are also impor­tant for the diag­no­sis of hyper­hidro­sis. There­fore, your doc­tor may ask you ques­tions about the impact of increased sweat­ing on your every­day qual­i­ty of life.

Test for the detection of hyperhidrosis

The diag­no­sis of hyper­hidro­sis is main­ly based on the inter­view and clin­i­cal eval­u­a­tion. In addi­tion, two more tests can be used to diag­nose hyper­hidro­sis: the Minor (starch iodine) test and the gravi­met­ric mea­sure­ment of sweat­ing rates.

Minor (starch iodine) test:

the Minor test allows the sweat-secret­ing area, for exam­ple, in the armpit, to be iden­ti­fied through dye­ing. For this pur­pose, an iodine solu­tion is applied to the skin area and then dust­ed with corn starch. Areas which are sweaty turn dark blue. The test does not pro­vide infor­ma­tion on the sever­i­ty of hyper­hidro­sis and is usu­al­ly only used if the area of exces­sive sweat­ing can­not be delim­it­ed with con­fi­dence.

Gravimetric measurement:

The amount of sweat per unit of time can be deter­mined by gravi­met­ric mea­sure­ment using fil­ter paper (such as a com­mon cof­fee fil­ter), stop­watch (test­ing usu­al­ly lasts 5 min­utes), and an ultra­fine scale. The sweat emit­ted in a cer­tain area of skin per 5 min­utes is caught in a fil­ter paper and then weighed with an ultra­fine scale. Abnor­mal sweat­ing in the area of the armpit is any­where above 50 mg per minute, while hyper­hidro­sis in the hands or feet is diag­nosed at 20–30 mg per minute.

Both tests are also suit­able for assess­ing the ther­a­peu­tic suc­cess of tap water ion­tophore­sis.