Clinical Dermatology

Diagnostic Hallmarks

1. Distribution - tips and sides of the digits, palms and soles
2. Clustering of minute, noninflammatory vesicles
3. History of recurrent episodes

Clinical Presentation

Dyshidrosis consists of minute, noninflammatory vesicles located along the lateral sides and tips of the digits. Individual vesicles are rarely more than 1 mm in diameter, but as the disease increases in severity, tight clustering can lead to coalescence and the formation of multiloculated bullae. In children, the toes and, in adults, the fingers are most often affected. In either, palmar or plantar skin may become involved as the disease progresses. The dorsal surfaces of the hands and feet are never involved initially, but when the disease evolves into a chronic condition, subsequent eczematous spread to these locations is possible.

Because of their location and size, the vesicles of dyshidrosis have a morphology quite different from those found in the other vesicular diseases. First, the vesicles are very small (less than 1 mm) and deeply situated and thus may not be elevated above the surface of the surrounding skin. Second, the thick stratum corneum that constitutes the vesicle roof lends an opaque, rather than translucent, color to the vesicle. Finally, the thick roof and deep location give the vesicles a certain toughness, they do not break open easily.

The range of symptoms in dyshidrosis varies greatly. Some individuals are asymptomatic, others describe significant pruritus or pain or both. If pruritus leads to scratching, dyshidrosis (a noninflammatory disease) is converted into its inflammatory counterpart, dyshidrotic eczema.

Patients with mild dyshidrosis will have only occasional intermittent attacks, and the skin returns to normal between episodes. When attacks occur frequently, the vesicular phase will be accompanied by the constant presence of xerosis, desquamation, cracking, and fissuring. This dry, chapped appearance, which is essentially that of irritant contact dermatitis, is prolonged and worsened by exposure to solvents such as soap and water.

The diagnosis of dyshidrosis is based on clinical findings. Biopsy is not ordinarily of help, and there are no confirmatory laboratory tests.

Course and Prognosis

Dyshidrosis sometimes begins in childhood, but most often its initial appearance is in early adult life. Thereafter, intermittent episodes can be expected. The interval between episodes is highly variable. Some people are free of disease for months at a time, whereas others have almost continuous involvement. The severity and frequency of episodes gradually decrease in late adult life, and the disease is rarely seen after age 60 years.

Pathogenesis

The word dyshidrosis is derived from dys meaning improper and hidrosis meaning sweating. The word was coined because it was originally thought that dyshidrosis represented sweat retention (miliaria) in obstructed sweat ducts. However, even though sweat ducts are occasionally found entering the vesicles on histologic examination, it is now believed that vesicle formation is only coincidentally related to sweating. An attractive, but unproven, hypothesis suggests that dyshidrosis is simply a variant of atopic dermatitis that occurs only on the hands and feet.

Stress and anxiety appear to play an important role in the precipitation of individual episodes, but it is not clear whether they alone are sufficient to cause the disease. In my experience, the presence of dyshidrosis correlates very well with the internalization of stress and anger. Further­more, the disease is particularly likely to be found in people with obsessive-compulsive traits. Such individuals often have difficulty relaxing even during relatively non­stressful intervals. Perhaps it is not surprising that have found, using informal surveys, that the prevalence of dyshidrosis in medical students is about 4 times that of the “normal” population! Hyperhidrosis (increased sweating) of the palms and soles sometimes accompanies the presence of dyshidrosis, but this may be related to the fact that such sweating in this location is under psychologic control.

Therapy

Dyshidrosis is a difficult condition to treat. Topical steroids, probably because of poor penetration, are of limited usefulness. Generally, it is necessary to use either the most potent strengths or a mid-strength steroid along with overnight use of plastic or Latex gloves . Unfortunately, sweating and irritation under these gloves often negate the beneficial effect of better steroid absorption. Patients with moderate to severe involvement are probably best treated with a burst of systemic steroids . This approach is momentarily very effective, but as might be expected, it does not delay the recurrence or reduce the severity of subsequent episodes.

In my experience, treatment of patients with frequent, severe episodes requires attention to related psychologic factors. For some patients, a simple explanation of the relationship between stress and the disease is sufficient. For others, tranquilizers, professional counseling, or behavior modification techniques may be necessary.

The chapping, cracking, and fissuring that often accompany and sometimes persist after the vesicular phase will require the continued use of topical steroids as well as liberal application of lubricants 6-8 times/day. When the feet are involved, additional modification of the environment is required. Leather-soled shoes should be substituted for rubber-soled tennis-type shoes, and cotton blend socks should replace those made totally of synthetic fibers. Moreover, shoes and socks should be removed as frequently as possible to allow for sweat evaporation and the application of lubricants.

This entry was posted on Wednesday, September 19th, 2007 at 9:29 am and is filed under Vesiculobullous Diseases. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.