The goal of the article selected this month, and which is the base for our present article today, is to learn and understand how the many common hyperpigmentation disorders arise from birth or in early infancy and how many of these problems potentially evolve over time. Depending on the specific pigmentation anomaly, some affect children only transiently during their early years, other pigmentation disorders can persist permanently throughout their lifetime ; they may be confined to localized areas of the body or in other rare cases can be systemic affecting large areas or even the entire body, although such generalized pigmentation occurs more rarely.

As with most pigmentation diseases a physical examination, including Wood’s lamp examination and a detailed history, is usually sufficient for diagnosis. Factors including the time of onset of the pigmentation, its distribution pattern, and the associated clinical or histopathologic or molecular findings are important factors in differentiating these disorders.

The article will focus on the 5 most commonly identified pigment anomalies present at birth or appearing in the first months of life in the young child, which are respectively : Transient hypermelanoses of the newborn, CAL spots, non-Blaschkoid and Blaschkoid segmental hypermelanoses, lentigines and lentiginoses and finally dermal melanocytosis.

  1. Transient hypermelanoses of the newborn.

The first pigment anomaly to focus on is called transient hypermelanoses of the newborn. It should be noted that at birth, a baby’s pigmentary system is not fully mature and some areas of a baby’s body may appear surprisingly hyperpigmented in comparison with the overall skin pigmentation of the baby’s skin. It is worth noticing that transient hypermelanoses is statistically more common with black newborns.

This anomaly, otherwise abbreviated into TPM, appears in the form of pustules present at birth that evolve into macular pigmentation. The content of the pustules is mostly neutrophilic, and the duration of the rash, especially the pigmentation, is longer than with other pigmentation anomalies. The pustules bear a close resemblance to erythema toxicum neonatorum and the eruptions are always present at birth. When TMP occurs, the lesions are located on the chin, neck, nape, upper chest, lower back and buttocks, and also on the lower abdomen and medial side of the thighs. Rarely, the scalp, palms, and soles can be affected. Often, pustules concentrate around the nipples and on pressure areas, and individual pustules dry out and often turn into flat, brownish crusts that can be removed easily by gentle scratching.

  1. Café-au-lait spots

The second skin pigmentation anomaly is what physicians and dermatologists commonly call CAL spots. CAL spots appear as uniform tan–brown round or oval macules with distinct both margins and variable border contour. These lesions almost inevitably grow in proportion to general body development during the first years of life and then they stabilize. Such spots are quite commonly observed at birth or in infants. Most children with CAL spots have no other associated abnormalities. However a study showed that 89% of Children with more than six large CAL spots large than 1.5cm in diameter, eventually develop neurofibromatosis, a genetic disorder that causes tumors to form on nerve tissue.

  1. Blaschkoid hypermelanosesis

The next skin anomaly to focus on has a complex word, but is rather easy to describe: non-Blaschkoid and Blaschkoid segmental hypermelanosesis in fact an expression of a cutaneous mosaicism of babies’ pigmentary system that shows as a hyperpigmented macule in a segmental pattern and presents early, that is to say in the first months of an infant’s life.

Most babies struck with such a pigmental anomaly are impacted at birth and/or in early childhood, and the macules they bear on their skin may continue to grow in proportion to skin expansion, just as CAL spots do. They usually appear anywhere on the skin and present a unilateral aspect with a sharp cutoff at the midline. Sometimes however, it so happens that they follow a checkerboard pattern or affect large Blaschko’s lines – they are lines of normal cell development in the skin which are invisible under normal conditions, but may become apparent in some rare cases such as this one.

  1. Lentigines

The fourth type of skin pigmentation abnormality is lentigines and lentiginoses. First, it is worth noticing that lentigines may be exceptionally present at birth. But when present, the typical lentigines, or lentigo simplex, is present as a discrete, small oval or circular macule of tan, brown of even black color, and which may appear on any part of the skin or even be located on mucous membranes.

One important fact about the multiple lentigines syndrome, also known as LEOPARD syndrome, is that it is rarely diagnosed at birth. The acronym LEOPARD describes the following features: lentigines, lesions noted most prominently on the face and trunk that increase in number as the young children grow older, as well as a number of other non-skin pigmentation related problems.

There is also another nother multi-systemic disease associated with lentigines, and it is named the Peutz–Jeghers syndrome. It is an autosomal-dominant pigmentation problem which consists of multiple lentigines grouped around the mouth area and also in gastrointestinal hamartomas (benign malformation) situated most densely in the jejunum. Lesions for this syndrome may occur in infancy, however, unlike other lentiginoses, lesions may disappear completely during adolescence.

  1. Dermal melanocytosis

The last of the hyperpigmentation problems to mention here is Dermal melanocytosis. DM for short, is also commonly called the Mongolian Spot (MS), and is a hyperpigmented macule or even a patch present at birth or shortly after a baby is born. DM mostly occurs on Asian, black, and dark white-skinned babies. Form include Nevus

Mongolian spots, are typically organized as being sacral or extrasacral, and more than 75% of lesions occur in the sacrogluteal area of the body. The typical MS is noted at birth and presents as a blue–green to blue–gray irregular patch with indefinite margins. It may increase in size for 1–2 years and reach its maximum color intensity at around 1 year. Depending on the babies observed, the lesion may vary in size from a few millimeters to more than 10 cm. Eventually, the MS typically disappears completely when children usually reaches around 4 years old.

The research document article upon which this article is based is entitled : Diagnosis of some common and uncommon hyperpigmentation disorders in children” ; was written by AlainTaıeb, Khaled Ezzedine and Fanny Morice-Picard. It was published in 2014 by Elsevier Taiwan LLC.  The link to the document is as follows: https://www.sciencedirect.com/science/article/pii/S1027811714000457

Several times a year, NUNII will bring to its readers’ attention condensed versions of breakthrough research articles dealing with hyperpigmentation problems in order to popularize knowledge regarding hyperpigmentation research and development, thus making available more facts and figures pertaining to this field of expertise.