Visual Diagnosis in Pediatrics
1st Edition

70
Hypopigmented Rashes
George A. Datto III
Approach to the Problem
Change in skin pigmentation are often noticed by parents and brought to the attention of clinicians. Hypopigmentation is more easily appreciated in darker-skinned individuals when an increase in color contrast is present between the rash and the normal pigmented skin. Hypopigmentation results from a loss of melanin within the epidermal keratinocytes. Diseases causing hypopigmentation range from benign transient conditions to those that can be associated with significant systemic complications.
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DIAGNOSIS ICD-9 DISTINGUISHING CHARACTERISTICS DISTRIBUTION ASSOCIATED FINDINGS COMPLICATIONS PREDISPOSING FACTORS
Postinflammatory Hypopigmentation 709.0 Irregular patches at sites of previous dermatitis Sites of previous skin inflammation or trauma None None Insect bites
Contact dermatitis
Atopic dermatitis
Seborrheic dermatitis
Tinea Versicolor 111.0 Macules with fine scale
Color depends on contrasting skin pigment
Neck
Chest
Upper back
Upper arms
None None Malassezia furfur
Pityriasis Alba 696.5 Macules with fine scale Face
Upper trunk
Proximal extremities
None None Often present in individuals with atopy
Vitiligo 709.01 Well-circumscribed macules Face—eyes and mouth
Hands, feet, elbows, knees, and ankles
None Autoimmune disorders in adults Positive family history
Tuberous Sclerosis 759.5 Congenital small macules Posterior trunk
Extremities
Facial angiofibroma
Shagreen patch
Periungal fibroma
Cardiac rhabdomyomas
Seizures
Mental retardation
Autosomal dominant
60% new mutations in genes coding for hamartin and tuberin
Hypomelanosis of Ito 709.0 Congenital hypopigmented whorls Trunk with midline demarcation Strabismus
Nystagmus
Seizures Xp II mutation
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Figure 70-1 Postinflammatory hypopigmentation following a diaper dermatitis. (Courtesy of George A. Datto, III, MD.)
Figure 70-2 Tinea versicolor. Hypopigmented scaly lesions on the back of a darkly pigmented adolescent. (Courtesy of George A. Datto, III, MD.)
Figure 70-3 Tinea versicolor under Wood’s lamp. Note the blue-whitish fluorescence. (Courtesy of Paul S. Matz, MD.)
Figure 70-4 Pityriasis alba. (Courtesy of George A. Datto, III, MD.)
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Figure 70-5 Vitiligo. (Courtesy of Paul S. Matz. MD.)
Figure 70-6 Segmental vitilgo on the foot of a child. (Courtesy of George A. Datto, III, MD.)
Figure 70-7 Tuberous sclerosis. Hypopigmented “confetti” macules on the back of a child with tuberous sclerosis. (Courtesy of George A. Datto, III, MD.)
Figure 70-8 Hypomelanosis of Ito. Linear swirl pattern of hypopigmentation on abdomen. (Courtesy of George A. Datto, III, MD.)
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Other Diagnoses to Consider
  • albnism
  • Piebaldism
  • Nevus depigmentosus
  • Nevus anemicus
Suggested Readings
Dohil MA, Baugh WP. Vascular and pigmented birthmarks. Pediatr Clin North Am. 2000;47(4):783–812.
Hurwitz S. Clinical pediatric dermatology. 2nd ed. Philadelphia: WB Saunders; 1993:458–465.
Weston WL, Lane AT, Morelli JG, eds. Color textbook of pediatric dermatology. 3rd ed. St. Louis: Mosby; 2002:247–250.