Seborrheic dermatitis

Seborrheic dermatitisChronic papulosquamous conditionOccur on sebum-rich area of scalp, face and trunkOccur as an isolated condition or in conjunction with other disorder such as blepharitis, acne vulgaris, ocular rosaceaVaries from mild dandruff to exfoliative erythroderma

Seborrheic dermatitis (cont.)Aggravated by change in humidity, change in season, trauma (e.g. scratching) or emotional stress Associated with several systemic disease include AIDS, zinc deficiency, Parkinson disease Frequently seen in patient who received psoralen with UVA therapy

Causative factorMalassezia globosaSebum production Genetic susceptibility for inflammatory response

Malassezia and seborrheic dermatitisLipophilic yeastFound in normal skinResearch document supported relation between Malassezia and seborrheic dermatitis :clinical response to antifungal drug :increase in number of Malassezia in recurrence disease

CausesMalassezia are not the cause but are a cofactor link to T-cell depression, increase sebum level and activation of the alternative complement pathwaySkin barrier dysfunction prone to diseaseMedication that induced flare up : auranofin, aurothioglucose, buspirone, chlorpromazine, cimetidine, ethionamide, gold, griseofulvin, haloperidol, interferon Alfa, lithium, methoxsalen, methyldopa, phenothiazines, psoralens, stanozolol, thiothixene and trioxsalen

Epidemiology Occurrence 1-3%Variable age range include infant through adultIncrease rate of occurrence in infant and 4-5th decade of lifeMale > femaleAfrican-American > Caucasian

Epidemiology (cont.)34-83% found in AIDSHigher rate of occurrence in DM, obesity, malabsorption, Parkinson disease, epilepsy

Etiology UnclearSebum and lipid level:increase sebum and lipid level in Parkinson disease, African-American > Caucasian:large and active sebaceous gland in newborn infant

Etiology (cont.)Immunologic response :depress T-cell function lead to increase Malassezia growth:increase natural killer cell activation:increase inflammatory interleukinMedication induced :found in Parkinson treated with specific neuroepileptic drug

Clinical Depend on age, skin type, presence or absence of concurrent systemic illnessDry and flaky with white scale or greasy with crustingSkin type 4-6 :reduce visible erythema:hypo or hyperpigmented

Clinical (cont.)Increase in winter and early springRemission commonly in summer

Clinical finding in newborn infantScale located throughout the scalp but also on face, chest, groin, neck, ears and eyelidCradle cap and napkin dermatitis appearanceRelated to sebum overproduction

Clinical finding in newborn infant (cont.)Severe generalized seborrheic dermatitis may represent Leiner disease (exfoliative disorder with anemia, diarrhea, immunodeficiency, concomitants bacterial and candidial infection

Clinical finding in adult Involved scalp, face, chest, axillae, submammary area, groin, gluteal regionScalp and face involvement:most prominent around eyebrows, perinasal skin, postauricular area, ears, eyelids

Clinical finding in adult (cont.):may extend from frontal scalp onto upper foreheadPerinasal and post auricular skin can appear either hypopigmented, hyperpigmented, erythematousCrusting may be seen in inner ear and ear canal

Clinical finding in adult (cont.)Chest, axillae, groin, gluteal involvement is usually scaly with hypopigmentation or erythema beneath the scaleOccasionally bacterial superinfection

Clinical finding in immunocompromiseSimilar to normal adult but more extensiveMore visible inflamed skinInvolvement include blepharitis, Meibomian gland occlusion result in scaling and burning of eyelidsDiffuse lesion at axillae, extremities and groin

Clinical finding in immunocompromise (cont.)Generalized seborrheic erythroderma is rare but more often May presented bacterial, candidial, dermatophyte superinfectionMoist and extreme erythema plaques at torso and extremities

Histopathology Spongiotic dermatitisMarked spongiosis, acanthosis, hyperkeratosisClassic finding :parakeratosis, neutrophilic infiltrate, scale crust at the opening of infundibulum of hair follicle, psoriasiform hyperplasia of epidermis

Histopathology (cont.)Some degree of epidermal rete ridge elongationIn immunocompromise : superficial perivascular infiltration with plasma cell and neutrophils, leukocytoclasia, keratinocyte necrosis within epidermis

Histology of seborrheic dermatitisPerifollicular parakeratosis rim in seborrheic dermatitis

Differential diagnosis in childrenContact dermatitisAtopic dermatitisTinea capitis/ faceiiCandidiasisMultiple carboxylase deficiencyBiotin responsive dermatitisScabiesImpetigoPsoriasis

Differential diagnosis in adultPsoriasisPityriasis roseaContact dermatitisSLEAtopic dermatitis

CandidiasisRosaceaImpetigoTinea versicolorSarcoidosis

Treatment Early treatmentBehavior modification to reduce excoriationAvoid shampoo and topical product that dry the hair and skin

Treatment (cont.)Steroid :low and middle potency:may increase recurrence rate:rebound effect :discourage except for short term use

Treatment (cont.)Antifungal drug:ketoconazole:ciclopiroxolamine:selenium sulfide

Treatment (cont.)Other ingredients:zinc pyrithione:coal tar:salicylic acid:sodium sulfacetamide:olive oil or mineral oil compresses with warm water

Treatment (cont.):lithium succinateTopical immunomodulator:topical tacrolimus and pimecrolimus:antifungal activity:FDA not currently approved:avoid side effect associated with topical corticosteroid

Clinical study of topical immunomodulator70% or greater clearance after 1% tacrolimus ointment in seborrheic dermatitisA double-blind, vehicle controlled 4 wks. trial randomized patients with seborrheic dermatitis:1% pimecrolimus effective and well tolerated for moderate to severe facial seborrheic dermatitis:efficacy as early as 2 wks.

Clinical study of topical immunomodulator (cont.)Open-label pilot trial in 5 African-American seborrheic dermatitis patients with hypopigmentation:1% pimecrolimus cream for 16 wks.:marked decrease severity:improve hypopigmentation

Clinical study of topical immunomodulator (cont.)Open-label pilot trial of seborrheic dermatitis in 5 African-American with associated hypopigmentation:1% pimecrolimus cream for 16 wks.:marked decrease severity of disease:improved hypopigmentation

Treatment (cont.)Narrow band UVB phototherapy:18 patients was given treatment 3 time/wk until complete clearing or max. 8 wks.:6 complete clearance and 12 marked improved:relapse all patients after average 3 wk.:safe and effective in severe seborrheic dermatitis

Seborrheic dermatitis and biotinBreast milk is deficient in biotin than cows milk and aggravated by poor maternal nutrition4 extensive seborrheic dermatitis infant (Leiners disease)Dramatically improve after biotin injection in nursing mother