Seborrheic dermatitis affects the s...

Seborrheic dermatitis affects the scalp, central face, and anterior chest. In adolescents and adults, it ofttimes presents as scalp scaling (dandruff). Seborrheic dermatitis also may cause mild to marked erythema of the nasolabial gather often with scaling. Stress can cause flare-ups. The scales are greasy, not dried as commonly thought. An remarkable generalized form in infants may be linked to immunodeficiencies. Topical therapy primarily consists of antifungal agents and low-potency steroids. modern topical calcineurin inhibitors (immunomodulators) sometimes are administered. (Am Fam Physician 2006;74:125-30 Copyright [C] 2006 American Academy of Family Physicians.)

Seborrheic dermatitis can affect patients from infancy to not new age. (1-3) The condition chiefly commonly occurs in infants within the first three month of life and in adults at 30 to 60 years of age. In adolescents and adults, it usually nears as scalp scaling (dandruff) or as mild to marked erythema of the nasolabial pen during times of stress or nap deprivation. The latter type look afters to affect men more oftentimes than women and often is precipitated by dint of emotional stress. An uncommon generalized form in infants may be linked to immunodeficiencies.

Seborrheic dermatitis and pityriasis capitis (cradle cap) are often met with in early childhood. According to the same survey of 1,116 children, (4) the overall age- and sex-adjusted prevalence of seborrheic dermatitis was 10 percent in striplings and 9.5 percent in girls. The highest prevalence occurr in the first three month of life, decreasing rapidly from one year of age, and slowly decreasing above the next four years. (4) greatest in number patients (72 percent) had minimal to mild seborrheic dermatitis. Pityriasis capitis occurr in 42 percent of the children examined (86 percent had a minimal to mild case).4 Prevalence estimates for older [i]role[/i]s are consistently higher than estimates for the general population. (5)

Etiology

Despite the high prevalence of seborrheic dermatitis, little is known about its etiology. However, several factors (eg hormone on a levels fungal infections, nutritional deficits, neurogenic factors) are associated with the condition. The possible hormonal link may explain for what cause [i]or[/i] reason the condition appears in infancy, disappears spontaneously, then reappears more prominently after puberty. A more causal link appear to bes to exist between seborrheic dermatitis and the proliferation of Malassezia species (eg Malassezia scurf Malassezia ovalis) found in normal dimorphic human flora. (6-8) Yeasts of this genus predominate and are lay the foundation of in seborrheic regions of the material part that are rich in sebaceous lipids (eg head, body upper back). A causal relationship is implied because of the ability to isolate Malassezia in patients with seborrheic dermatitis and by dint of its therapeutic response to antifungal agents. (9) A similar link has been refer toed in studies of patients with seborrheic dermatitis that is associated with acquired immunodeficiency syndrome (AIDS). (1011) Seborrheic dermatitis also may be associated with nutritional deficiencies, if it be not that there is no firm linkage.

An altered essential fatty acid pattern may be important in the pathogenesis of infantile seborrheic dermatitis. Serum essential fatty acid patterns from 30 children with the condition hinted a transient impaired function of the delta-6 desaturase enzyme (12) A neurogenic theory for the unfolding of seborrheic dermatitis may account for its association with parkinsonism and other neurologic disorders, including postcerebrovascular accidents, epilepsy, central nervous order trauma, facial nerve palsy, and syringomyelia induced by the agency of neuroleptic drugs with extrapyramidal imports (7) It may be confined to the syringomyelia-affected area or to the paralyzed side in a patient with hemiplegia. However, no neurotransmitters have been identified in this context

Classification

Adolescent and adult seborrheic dermatitis usually starts as mild greasy scaling of the scalp with erythema and scaling of the nasolabial enclosures (Figure 1) or the postauricular skin. The scaling frequently is concurrent with an oily complexion and appears in areas of increased sebaceous gland activity (eg auricles, beard area, eyebrow body [flexure and inframammary areas; Figure 2]) Sometimes the central face is involved (Figure 3) Blepharitis, with meibomian gland occlusion and abscess formation, otitis externa, and coexistent acne vulgaris or pityriasis versicolor, may be evident.

[FIGURES 1-3 OMITTED]

couple types of seborrheic dermatitis may appear upon the chest--a common petaloid stamp and a rarer pityriasiform stamp (2) The former starts as small, reddish-brown follicular and perifollicular papules with greasy scales. These papules become patches that compare the shape of flower petals or a medallion (medallion seborrheic dermatitis). The pityriasiform shadow often has generalized macules and patches that counterfeit extensive pityriasis rosea. These patches rarely about an eruption so generalized that it causes erythroderma.