Guest Commentary: Skin disease comorbidities: Understanding simultaneous disorders

Key Points

Dermatologists have long recognized the presence of systemic disease associated with skin disorders. In fact, it is the subject of classic textbooks written or edited by the likes of Dr. Irwin Braverman.

The presence of comorbid states associated with skin disease, however, has been driven largely by the collection of case reports and anecdote, and has focused on less-than-common skin disorders.

Recent studies using large patient databases have allowed for identification of previously unrecognized or poorly characterized comorbidities associated with common skin diseases such as psoriasis.

While the specific data relating to particular associations is, without question, valuable, perhaps an equally valuable product of these studies is the generation of a novel perspective.

Historically, the association of clinically relevant extracutaneous dysfunction was generally linked to relatively uncommon skin diseases, such as vasculitis or dermatomyositis.

More recent analysis of patients with common skin diseases, combined with the use of large clinical databases, has raised the possibility that comorbid states associated with common skin disorders may be the rule rather than the exception.

Frequency

If common skin diseases are associated with frequent and clinically relevant comorbid states, it raises a number of important questions that can directly impact patient care.

First and foremost, it raises the fundamental question of what is at stake when treating skin disease. What comorbidities are present and with what specific skin disorders? What type of extracutaneous disease exists in specific patient populations, and to what extent are patients impacted in terms of life expectancy or quality of life?

For the most part, we do not know the answers to these questions as they relate to even the most common skin diseases.

Subsequent decisions regarding the value of treatment and weighing the risks and costs involved are remarkably difficult within a data-poor environment.

Collaboration

Studies needed to answer these important questions will be best addressed using collaborative teams from multiple disciplines with complementary expertise.

To that end, the first comorbidity conference brought together a host of experts from academia and industry, both within and outside of dermatology.

While not completely definitive, the work linking psoriasis to cardiovascular disease can serve as a template to look at other associations.

The existence of multiple other databases will allow us to apply similar methodologies to the study of psychiatric comorbidities, the existence of which is strongly suspected but not well-substantiated.

Similarly, how often skin toxicity develops as a consequence of treatment for non-skin disorders is not well-defined.

Furthermore, how often skin toxicity actually compromises treatment protocols for malignancies, infectious diseases or neurological diseases is only crudely characterized.