Genodermatoses
Featuring faculty, Dr. James Treat
Dr. James Treat began an engaging lecture this morning on genodermatoses with the emphasis that a dermatological manifestation may be the first marker of a systemic genetic condition. As dermatology providers, we are “the gateway into the medical system’ and as such it’s essential to know when and to whom to refer. In fetal development, the skin, the eyes and the brain all evolve from the same ectodermal cells, therefore, it is important to recognize skin manifestations that may be an early sign of related neurological or ophthalmologic conditions. Additionally, when evaluating a pediatric patient for the first time , it is typically helpful to evaluate the birth parents to see if the child has obvious varied facial features from their parents.
As dermatology providers, we are “the gateway into the medical system’ and as such it’s essential to know when and to whom to refer.
It is well known café au lait spots can be an early clue of NF1 (neurofibromatosis 1). Of interest, Dr. Treat revealed up to 51% OF NF1 patients will present with nevus anemicus. Clinically, when nevus anemicus is rubbed with an alcohol pad, the white part stays white due to vasoconstriction, while the edges will become red from irritation of the alcohol pad. Many patients who present with NF1 do not have a family history and represent a new mutation. Work up of a newly diagnosed NF1 patient involves genetic testing, most often done in Alabama, an ophthalmological referral, evaluation of blood pressure and referral to a geneticist.
Next Dr. Treat discussed segmental pigmentary disorders. He reported the majority of these presentations are benign, but it is important to recognize when there are concerning features. Examples of when to worry include when pigmentation does not stop at midline, the pigmentation covers a broader area , pigmentation is found in multiple areas or if the pigmented patches have jagged edges on the margins ‘’like the coast of Maine”.
Dr. Treat went on to discuss nevus sebaceous and illustrated the differences in presentation in patients of color compared with Caucasian individuals. While it has been quoted up to 5-10% of nevus sebaceous may develop basal cell carcinomas within them, Dr. Treat believes the rate to be much lower than this. Changes to these lesions are most likely to occur after puberty. These lesions do not have to be removed, though since they are sebaceous in nature, acne may become a problem in these lesions. As with any skin finding, if it is larger than normal, it is important to think of other organ systems.
While it has been quoted up to 5-10% of nevus sebaceous may develop basal cell carcinomas within them, Dr. Treat believes the rate to be much lower than this.
Finally, Dr. Treat discussed the importance of considering a genetic condition when patients present with an unusually exuberant presentation of a common condition. He used a case presentation of a young patient who presented with hundreds of molloscum lesions who was diagnosed with a genetic immunodeficiency. Dr. Treat further reviewed tuberous sclerosis, cutaneous mosaicism, nevus comedonicus and epidermal nevus presentations.