Lesional Morphology and Assessment




Introduction


Newborn infant skin can manifest with an extraordinary array of conditions. Neonatal cutaneous findings may indicate transitory, benign processes such as erythema toxicum neonatorum, or may represent important harbingers of internal disease or genetic alteration, as might be observed in patients with herpes simplex virus infection or incontinentia pigmenti. Dermatologic manifestations are readily visible to the clinician, and it is often more efficient to first assess lesional morphology and then focus history-taking on the basis of the observed clinical findings. The timely identification and accurate diagnosis of skin findings in the newborn infant therefore relies on combining a comprehensive history with a meticulous physical examination, as well as on a proper understanding of physiologic differences between neonatal, pediatric, and adult skin that will influence both the diagnosis and the management of skin conditions appropriate to the neonate. This chapter reviews the principles of morphologic assessment in the term and preterm infant.




Reaction patterns


An understanding of the specialized reaction patterns is outlined in Tables 3.1–3.3 and Box 3.1 and, in conjunction with a comprehensive history and assessment of cutaneous morphology, will aid the clinician in making the proper dermatologic diagnosis.



TABLE 3.1

Primary lesions

Drawings reproduced with permission from Bolognia JL, Jorizzo JL, Rapini RP, eds. Dermatology. 3rd ed. St. Louis: Saunders; 2012.





















































































Primary lesions are defined as lesions that arise de novo and are therefore most characteristic of the disease process. The graphic representations are intended to demonstrate three-dimensional and topographic relationships and not necessarily the histology of the example shown.
MACULE EXAMPLES






Café-au-lait macules
A circumscribed, flat lesion with color change, up to 1 cm in size, although the term is often used for lesions >1 cm. By definition, they are not palpable Ash leaf macules, café-au-lait macules, capillary malformations
PATCH EXAMPLES






Hemangioma precursor
A circumscribed, flat lesion with color change, >1 cm in size Nevus depigmentosus, Mongolian spots, nevus simplex
PAPULE EXAMPLES






Umbilical granuloma
A circumscribed, elevated, solid lesion, up to 1 cm in size. Elevation may be accentuated with oblique lighting Verrucae, milia, and juvenile xanthogranuloma
PLAQUE EXAMPLES






Nevus sebaceus
A circumscribed, elevated, plateau-like, solid lesion, >1 cm in size Mastocytoma, nevus sebaceus
NODULE EXAMPLES






Juvenile xanthogranuloma
A circumscribed, elevated, solid lesion with depth, up to 2 cm in size Dermoid cysts, neuroblastoma
VESICLE EXAMPLES






Acropustulosis of infancy
A circumscribed, elevated, fluid-filled lesion up to 1 cm in size Herpes simplex, varicella, miliaria crystallina
BULLA EXAMPLES






Insect bite reaction
A circumscribed, elevated, fluid-filled lesion >1 cm in size Sucking blisters, epidermolysis bullosa, bullous impetigo
PUSTULE EXAMPLES






Transient neonatal pustular melanosis
A circumscribed, elevated lesion filled with purulent fluid, <1 cm in size. Pustules can be primary skin lesions or can initially be a vesicle that then becomes filled with cells or debris. Transient neonatal pustular melanosis, erythema toxicum neonatorum, infantile acropustulosis
WHEAL EXAMPLES






Drug eruption
A circumscribed, elevated, edematous, often evanescent lesion, caused by accumulation of fluid within the dermis Urticaria, bite reactions, drug eruptions
ABSCESS EXAMPLE






Abscess
A circumscribed, elevated lesion filled with purulent fluid, >1 cm in size. Pyodermas


TABLE 3.2

Secondary lesions

Drawings reproduced with permission from Bolognia JL, Jorizzo JL, Rapini RP, eds. Dermatology. 3rd ed. St. Louis: Saunders; 2012.










































Secondary lesions are characteristically brought about by modification of primary lesions, either by the individual or through the natural evolution of the lesion in the environment. The graphic representations are intended to demonstrate three-dimensional and topographic relationships and not necessarily the histology of the example shown.
CRUST EXAMPLES






Infected atopic dermatitis
Results from dried exudate overlying an impaired epidermis. Can be composed of serum, blood, or pus Epidermolysis bullosa, impetigo
SCALE EXAMPLES






Seborrheic dermatitis
Results from increased shedding or accumulation of stratum corneum as a result of abnormal keratinization and exfoliation. Can be subdivided further into pityriasiform (branny, delicate), psoriasiform (thick, white, and adherent), and ichthyosiform (fish scale-like) Ichthyoses, postmaturity desquamation, seborrheic dermatitis
EROSION EXAMPLES






Epidermolysis bullosa
Intraepithelial loss of epidermis. Heals without scarring Herpes simplex, certain types of epidermolysis bullosa
ULCER EXAMPLES






Aplasia cutis congenita
Full-thickness loss of the epidermis, with damage into the dermis. Will heal with scarring Ulcerated hemangiomas, aplasia cutis congenita
FISSURE EXAMPLES



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