CHAPTER 27

 
Seborrheic dermatitis is a chronic inflammatory disease of the seborrheic areas of the skin and the scalp. The disease is characterized by dry, moist or greasy scales and crusted yellowish patches. The disease is characterized also by itching , remission and exacerbation. Seborrheic dermatitis may be associated with certain systemic conditions such as diabetis,malabsorption syndrome, sprue, obese children and reaction to gold and arsenic.

The etiology of seborrheic dermatitis is not exactly known. It is considered as an inborn error of seborrheic diathesis. The fungus ;Pityrosporon ovale which is a saprophyte that depends on oily medium, is found in large number in the scalp of the seborrheic patients.

Predisposing factors such as high fat intake, stress and hyperhidrosis may play some role on the pathogenesis of seborrheic dermatitis. Susceptibility to Candida albicans and bacterial infection is usually common in patients having seborrheic dermatitis.

Clinical features

Seborrheic dermatitis is usually accompanied by hair falling and is a common cause of baldness in adults.

Itching is variable but usually it is mild.

Seborrheic dermatitis has a chronic course. The disease may become generalized accompanied by exfoliative dermatitis or generalized erythroderma known as "Leiner‘s disease.

1. Psoriasis: psoriasis is sometimes not easily differentiated from seborrheic dermatitis especially that of the scalp.The involvement of other seborrheic areas and the greasy scaly patches may help in the differential diagnosis. Psoriasis lesions do not usually extend and exceed below the hairlines in contrast to seborrheic dermatitis, which may extend to involve the eyebrow, eyelashes and the face.

2. Impetigo of the scalp and folliculitis. There is no greasy dandruff and the lesions are usually localized.

3. Pityriasis rosea: can be differentiated by the presence of the herald patch, characteristic distribution of lesions around the lines of ribs , peripheral adherent scale and the hypopigmented patches.

4. T. cruris and corporis: are characterized by the active edges of the lesions, dry non greasy scales and by detection of the causative fungi from scrapings from the active peripheral edge of the tinea lesions.

INFANTILE SEBORRHEIC DERMATITIS

Infantile seborrheic dermatitis is a term used to describe a clinical presentation, which may reflect a variety of different skin disorders such as cradle cap, intertriginous lesions, intertrigo, infantile psoriasis and Leiner‘s syndrome.

The incidence of atopic dermatitis with seborrheic dermatitis is so high that some infants with infantile seborrheic dermatitis would in any case be expected to develop atopic dermatitis.

P. ovale is part of the normal skin flora has a possible etiological role. This is supported by reports of the therapeutic response of seborrheic dermatitis to topical ketoconazole .

Seborrheic dermatitis in newborn and young children may need only mild medications in comparison with the adult seborrheic dermatitis .

1. Skin lesions

   Mild lesions of the skin improve usually with hydrocortisone ointment .

   Moderate cases : hydrocortisone ointment combined with tar or vioform (Lococorten tar , 

   Lococorten vioform ).

   Severe cases : Fluorinated steroids may be used taking into consideration the side effects .

   Topical preparations in combination of antibiotics or Itraconazole can be used in complicated cases with bacterial or fungal infections .

   In most cases of seborrheic dermatitis in infants and children , I use non-steroid Pufexamac in combination of antifungal and antibacterial preparation (Flogocid , Parfenac) . This is a safe medication , effective and gives good results .

2. Scalp lesions of seborrheic dermatitis :

• Mild cases: may need simply a mild shampoo (Head & Shoulder shampoo, Zincon shampoo) used every other day .

• Moderate cases : Hydrocortisone lotion ( Lococorten lotion ) , locoid scalp, elocom lotion with a mild shampoo .

• Severe cases: Fluorinated corticosteroid lotions may be needed for chronic recurrent , reluctant cases and a shampoo containing tar (Poly tar shampoo , Zeton shampoo) .

• Seborrheic dermatitis of the eyelids : Mild shampoo such as baby shampoo used several times and applying hydrocortisone ophthalmic ointment twice daily for a short period .

• Nizoral shampoo can be used for older children and adults for a short period can give good results . Selenium sulfide shampoo (Selsun ) is an effective in seborrheic dermatitis. Long use of such shampoos may cause hair falling. Care for the eyes during washing of the scalp, because these may cause irritation.

• Seborrheic dermatitis of the scalp is usually complicated by secondary bacterial infections such as folliculitis. Antibacterial lotion such as Erythrocin (Eryderm lotion) or clindamycin (Dalacin T lotion) can be applied twice daily to the scalp.

• Bacterial infections of the scalp should be treated before application of corticosteroids lotions, where the latter are postponed till controlling the bacterial infections. Oral antibiotics such as cephalosporins, Erythrocin, Zithromax may be indicated in severe extensive infections. Doxacyclines, Minocycline and Tetracyclines are not given for children but they have good effect in adults.

This is a mild form of seborrheic dermatitis, affecting newborn infants. The skin manifestations present with adherent and greasy scales involving the vertex of the scalp , usually accompanied by milia and comedones of the face.

Some authors consider that type is the continuation of the vernix caseosa, which covers the scalp of newborn after labor .

Erythematous, swollen and greasy yellowish adherent scales cover the scalp especially the vertex, and eyebrows. The lesion may extend to involve the neck , behind the ears, chest , axilla and intertriginous areas The patches have characteristic well-defined margins and usually symmetrical.

The areas may become macerated, fissured and are liable to secondary bacterial and fungal infections.

Management of mild forms of cradle cap is simple by rinsing the scalp with warm olive oil, which is left for few minuets, and the area is then combed gently, where the scales can be easily removed leaving the area free from scales.

The scalp later is cleaned with mild shampoo .

Shampoos containing selenium sulfide , salicylic acid , sulfur should be avoided in the newborn for the possibility of toxic absorption .

For older children: hydrocortisone alone  or in combination with salicylic acid (Locosalene, Dexalocal) can be applied gently. This may give good results.

Complicated cases with secondary bacterial or fungal infection can be treated accordingly using topical antibacterial preparation such as Muperacin cream or antifungal topical preparations such as Itraketocanazole cream .

Leiner‘s disease is considered a wide spread type of infantile seborrhoeic dermatitis with extensive erythematous and eczematous skin lesions .

Etiology

A defect of immunity in infants with functional inadequacy of the fifth component of complement (C5) is believed to be an important factor .

It is believed that the syndrome of C5 deficiency and Leiner‘s disease were one and the same .

This syndrome may be associated with general systemic manifestations such as diarrhea and weight loss .

Many of these infants improved when their diet was changed to rice water and cows‘ milk. It is also believed that breast-feeding was responsible for the illness.

Others consider Leiner‘s disease is a purely clinical entity that is characterized by:

1. Generalized seborrheic dermatitis.

2. Intractable severe diarrhea

3. Marked wasting and dystrophy .

4. Recurrent local and systemic infections .

5. ‘Familial Leiner‘s disease with C5 dysfunction is considered a more dangerous variant.

Most cases are severe and hospitalization is necessary .

Fluid and electrolytes balance .

Fresh plasma .

Steroids and antibiotics .

Dietary supplements of vitamin B complex including biotin are important.

1. Bonifazi E. Infantile seborrheic dermatitis: pathogenetic considerations and nosological aspects. Pediatr Dermatol News 1988; 7: 16-21.

2. Yates VM, Kerr Rei, Mackie R. Early diagnosis of infantile seborrheic dermatitis and atopic dermatitis-clinical features. Br J Dermatol 1983; 108: 6338.

3. Prince GE. Erythroderma desquamativa of the newborn infant. J Pediatr 1955; 47: 475-80.

4. Miller ME, Koblenzer PJ. Leiner‘s disease and deficiency of C5. J Pediatr 1972; 80: 879-80.

5. Evans DIK, Holzel A, MacFarlane H. Yeast opsonization defect and immunoglobulin deficiency in severe infantile dermatitis (Leiner‘s disease). Arch Dis Child 1977; 52: 691-5.

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