Pediatric emergency medicine trisk 461

griseofulvin (15 to 20 mg/kg/day in two divided doses) will usually resolve the problem Tinea Capitis Although tinea capitis is commonly caused by Microsporum species and Trichophyton tonsurans , the two forms have different clinical appearances The Microsporum species generally causes round patches of scaling alopecia ( Fig 88.21 ) Illumination of a lesion with a Wood lamp gives a blue-green fluorescence Kerion formation can occur as a swollen, boggy abscess The Trichophyton species usually causes scattered alopecia with seborrheic-like scaling, not always oval or rounded; the alopecia is irregular in outline with indistinct margins Normal hairs grow within the patches of alopecia At times, the hairs break off at the surface of the scalp, leaving a “black dot” appearance ( Fig 88.22 ) Diffuse scaling may simulate dandruff, and although minimal hair loss is present, it is not perceived Wood light examination of lesions caused by Trichophyton species does not produce fluorescence The organism can cause a folliculitis, suppuration, and kerion formation ( Fig 88.23 ) Diagnosis is made by culturing the affected scalp area The clinician should consider the presence of tinea capitis when a nonresponsive seborrheic or atopic dermatitis of the scalp is present, black dots are seen, occipital adenopathy is present, or increased scaling follows the use of topical steroids If a kerion is present, the swelling (allergic reaction to the fungus) can be controlled by a combination of griseofulvin and prednisone It is important to treat with an oral agent and not simply with a topical shampoo or cream; the latter is ineffective and can temporarily improve the tinea capitis while rendering subsequent cultures falsely negative, greatly complicating the case FIGURE 88.21 Tinea capitis with round patches of scaling alopecia FIGURE 88.22 Black dot tinea capitis FIGURE 88.23 Inflammation characteristic of a kerion In the differential diagnosis of patchy hair loss, as is seen in tinea capitis, the clinician should consider alopecia areata ( Fig 88.24 ) However, with alopecia areata, no inflammation or scaling of the scalp occurs Trichotillomania (also trichotillosis ), the term given to the habit children develop of rubbing, twirling, or playing with their hair to the point that the hair breaks and is lost in irregular sometimes geometric patches, should also be considered Hairs are characteristically of different length within the affected area, indicating breakage at different times In addition, there is no scaling or inflammation typically seen Traction alopecia occurs with certain hairstyles Hair is lost at the margins of the hairline with the ponytail style or frequent use of tight hair styles At times, papules or pustules occur where the skin has been disrupted by the traction Infants who are left on their backs for long periods may lose hair at the occiput from the constant friction in that area