Seborrheic Dermatitis: Dandruff, Cradle Cap…

About 2-5% of the population has some form of Seborrheic Dermatits, which is more commonly known as dandruff and cradle cap.  It is a chronic, superficial, inflammatory disease with a predilection for the scalp, eyebrows, eyelids, nasolabial creases, lips, ears, sternal area, axilla, submammary folds, umbilicus, groin and gluteal creases.  The scale is often yellow and greasy in appearance…on an erythematous base.  Itching may be severe.  The severity and extent of involvement is wide ranging from mild to severe.

Variations extend beyond the typical areas and can spread across the forehead, ears, postauricualr regions and the neck.  In extreme cases the entire scalp is covered by a greasy, dirty crust with an offensive odor.  In Infants, yellow or brown scaling lesions on the scalp, with accumulated adherent epithelial debris, is called “cradle cap.”  Seborrheic dermatitis may be associated with internal diseases, such as Parkinson’s disease, diabetes mellitus, sprue, malabsorption disorders, epilepsy, neuroleptic drugs, and HIV disease.

CAUSES:  The etiology of this common disorder is complex and unresolved.  It may be related to the presence of lipophilic yeast Malassezia ovalis (Pityrosporum ovale), which produces bioactive indoles, oleic acid, malassezin and indole-3-carbaldehyde.  Patients with Seborrheic Dermatitis often show upregulation of interferon, expression of interleukin-6, expressed as interleukin-1beta, and interleukin 4.

TREATMENT:  A variety of over the counter and prescription treatments are available…tar shampoos, selenium sulfide shampoos, nizoral shampoo, topical steroid preparations, topical calcineurin inhibitors, tacrolimus, zinc pyrithionne, resorcin and a variety of antifungal agents to include nizoral (ketoconazole), ciclopirox, and even oral intraconazole, terbinafine and fluconazole.  Secondary infections may occur requiring oral antibiotics such as tetracyclines.  The wide range of treatment options to include antibiotics, steroids and antifungal agents which may be completely contraindicated to mix…for example…systemic and topical steroids often exacerbates and worsens cutaneous fungal disorders.  Much is yet to be learned about the cause of this very common affliction.  To read more about Seborrheic Dermatitis click HERE and HERE.