Idiopathic acquired generalized anhidrosis due to occlusion of proximal coiled ducts

Prognosis after steroid pulse therapy and seasonal effect in acquired idiopathic generalized anhidrosis

Acquired idiopathic generalized anhidrosis is a rare disease with unknown etiology. Sudden loss of sweating function adversely affects young patients' quality of life. Although systemic corticosteroid therapy is the most frequently reported treatment for the disease, its effectiveness is controversial because of the risk of recurrence. To assist clinical decision-making regarding whether to use steroids, we investigated the treatment responsiveness and recurrence rates in patients undergoing steroid pulse therapy and explored factors affecting these rates. We retrospectively collected data of 124 patients who received steroid pulse therapy to calculate the rate of responsiveness to the therapy. We also conducted a time-to-event analysis in a cohort of 57 patients who responded to steroid pulse therapy to estimate the recurrence rate after the therapy. As a result, the response and recurrence rates were 73% and 48%, respectively. Recurrence occurred within 1 year in most patients. The overall effectiveness of steroid pulse therapy was estimated to be 57% considering the recurrence rate. A delay from onset to treatment and younger age appeared to be negative factors for effectiveness. Moreover, we found a significant seasonal effect on both treatment and recurrence: autumn was the worst season for acquired idiopathic generalized anhidrosis in Japan. Our study revealed that steroid pulse therapy can be expected to be effective in half of treated patients. We recommend starting the therapy promptly after the diagnosis; however, it is also worth considering the season for treatment planning.

Clear cell injury associated with reduced expression of carbonic anhydrase II in eccrine glands consistently occurs in patients with acquired idiopathic generalized anhidrosis

Acquired idiopathic generalized anhidrosis (AIGA) is characterized by anhidrosis/hypohidrosis without other autonomic and neurological dysfunctions. It has been believed that AIGA patients usually present no significant morphological alterations in the secretory portion of eccrine glands consisting of clear, dark and myoepithelial cells. However, we have recently revealed morphological damage of eccrine glands in AIGA patients by immunohistochemistry. Moreover, inhibitory side-effects against carbonic anhydrase II (CA II) by the antiepileptic reagent topiramate have been reported to cause heat intolerance mimicking AIGA. To determine the precise morphological changes and CA II expression in eccrine glands of AIGA patients, electron microscopic observation and immunohistochemistry were applied to skin of both anhidrotic (non-sweating) and normohidrotic (sweating-preserved) sites, taken from each patient clinically diagnosed with AIGA. We found consistent clear cell injury in eccrine glands in anhidrotic skin samples of AIGA patients. Electron micrographs demonstrated edematous, swollen and destructive damage in clear cells of eccrine glands from non-sweating areas of almost all AIGA patients. Immunohistochemically, clear cells showed reduced CA II expression that was heterogeneously distributed in non-sweating skin. Some areas showed almost complete loss of CA II expression in spite of preserved dark cells, and others showed mild or moderate loss of it. Selective destruction of clear cells resulting in heterogenous atrophy in AIGA patients may be important to elucidate its etiology.

Acquired Idiopathic Generalized Anhidrosis

Acquired idiopathic generalized anhidrosis is a rare condition, where the exact pathomechanism is unknown. We report a case of acquired idiopathic generalized anhidrosis in a patient who later developed lichen planus. Here an autoimmune-mediated destruction of sweat glands may be the probable pathomechanism.

Acquired idiopathic anhidrosis: a diagnosis often missed

BACKGROUND

Acquired idiopathic anhidrosis (AIA) is an uncommon entity characterized by anhidrosis in the absence of any neurologic or sweat gland abnormalities.

OBJECTIVE

The aim of this study was to characterize the clinical profile in a cohort of patients diagnosed with AIA at a tertiary dermatologic center.

METHODS

We retrospectively evaluated cases seen during a 10-year period. Inclusion criteria included all cases of generalized or partial anhidrosis with no obvious causes, confirmed by provocative starch-iodine sweat test. Ectodermal dysplasias, poral dysfunction from chronic dermatoses, autonomic dysfunction, and drug-induced causes were excluded.

RESULTS

Fifteen Chinese patients were diagnosed with AIA, mostly healthy young men with no significant medical or drug history, with variable extent of body surface area involvement. Serum immunoglobulin E, a complete blood cell count, thyroid function test, and antinuclear antibody levels were unremarkable. Anhidrotic areas revealed normal eccrine appendages with mild perivascular and perieccrine lymphocytic infiltrate. There were no neurologic abnormalities.

LIMITATIONS

This was a retrospective study.

CONCLUSION

Our study shows that AIA seems to be a heterogeneous group with no major dysfunction other than anhidrosis. Proper recognition and evaluation is paramount, especially for at-risk populations, so that appropriate measures on the prevention of heat injuries can be instituted.

Forkhead transcription factor FoxA1 regulates sweat secretion through Bestrophin 2 anion channel and Na-K-Cl cotransporter 1

Body temperature is maintained in a narrow range in mammals, primarily controlled by sweating. In humans, the dynamic thermoregulatory organ, comprised of 2-4 million sweat glands distributed over the body, can secrete up to 4 L of sweat per day, thereby making it possible to withstand high temperatures and endure prolonged physical stress (e.g., long-distance running). The genetic basis for sweat gland function, however, is largely unknown. We find that the forkhead transcription factor, FoxA1, is required to generate mouse sweating capacity. Despite continued sweat gland morphogenesis, ablation of FoxA1 in mice results in absolute anihidrosis (lack of sweating). This inability to sweat is accompanied by down-regulation of the Na-K-Cl cotransporter 1 (Nkcc1) and the Ca(2+)-activated anion channel Bestrophin 2 (Best2), as well as glycoprotein accumulation in gland lumens and ducts. Furthermore, Best2-deficient mice display comparable anhidrosis and glycoprotein accumulation. These findings link earlier observations that both sodium/potassium/chloride exchange and Ca(2+) are required for sweat production. FoxA1 is inferred to regulate two corresponding features of sweat secretion. One feature, via Best2, catalyzes a bicarbonate gradient that could help to drive calcium-associated ionic transport; the other, requiring Nkcc1, facilitates monovalent ion exchange into sweat. These mechanistic components can be pharmaceutical targets to defend against hyperthermia and alleviate defective thermoregulation in the elderly, and may provide a model relevant to more complex secretory processes.

Virilizing para-adrenocortical adenoma associated with idiopathic-acquired generalized anhidrosis in an adolescent girl

Adrenocortical tumors are rare in childhood and adolescence. Virilization, alone or in combination with signs of overproduction of other adrenal hormones, is the most common clinical presentation. Here we report an unusual case of an African-American female adolescent presenting with idiopathic acquired generalized anhidrosis, dysregulation of body temperature, absence of adult body odor and dry skin in the face of a virilizing para-adrenocortical adenoma. Virilization signs regressed soon after removal of the tumor, but normalization of the 3alpha-androstenediol glucuronide (3alpha-AG) took longer compared to other measurable androgens; accompanied by anhidrosis. The association of remitting anhidrosis with normalized levels of 3alpha-AG suggests it might be a possible mechanism for anhidrosis. High 3alpha-AG levels might implicate the increased peripheral conversion of weak pro-androgens with different biochemical structure. We recommend obtaining 3alpha-AG beside other androgens in virilized patients with atypical dermatological symptoms in the face of hyperandrogenism.

Successful steroid treatment of acquired idiopathic partial hypohidrosis

The pathogenesis of idiopathic-acquired hypohidrosis remains unknown, and no specific causes have yet been established. We report a 34-year-old man with acquired idiopathic hypohidrosis successfully treated with prednisolone. The patient noticed heat intolerance and hypohidrosis of the pectoral and back during the summer. No systemic disease or neurological findings were identified. Eccrine sweat glands displayed infiltration by inflammatory cells, with immunoglobulin G and C3 deposition in the basement membrane. Steroid therapy improved the hypohidrosis. An immunological pathogenesis could be a major factor in idiopathic-acquired hypohidrosis.