Chapter Contents
Introduction 820
Structure and function of the neonatal skin 820
Pustules, blisters and erosions in the neonate 821
Benign transient neonatal disorders presenting with sterile pustules 821
Toxic erythema of the newborn 821
Transient neonatal pustular dermatosis (transient neonatal pustular melanosis) 821
Infantile acropustulosis 822
Eosinophilic pustulosis (eosinophilic pustular folliculitis) 822
Miliaria 822
Neonatal cephalic pustulosis and neonatal acne 823
Infective conditions presenting with pustules, blisters or erosions 823
Varicella 823
Herpes simplex 823
Impetigo 823
Staphylococcal scalded-skin syndrome 823
Candida 824
Scabies 824
Syphilis 824
Dermatological conditions presenting with pustules, blisters or erosions 824
Epidermolysis bullosa 824
Mastocytosis 825
Bullous ichthyosis 825
Incontinentia pigmenti 825
Neonatal pemphigus 826
Neonatal herpes gestationis 826
Congenital erosive and vesicular dermatosis 826
Disorders with systemic significance which can present with neonatal pustules, blisters or erosions 826
Zinc-deficiency dermatosis 826
Langerhans cell histiocytosis 827
Hyper-IgE syndrome (Job syndrome) 827
Myeloproliferative disorder in Down syndrome 827
Porphyrias 827
Other transient neonatal conditions 827
Sebaceous hyperplasia 827
Milia 827
Sucking calluses or sucking pads 827
Sucking blisters 827
Subcutaneous fat necrosis 827
Neonatal lupus erythematosus 828
The red scaly baby 828
Seborrhoeic dermatitis 828
Atopic dermatitis 828
Psoriasis 828
Ichthyoses 829
Collodion baby phenotype 829
X-linked ichthyosis 829
Netherton syndrome 829
Harlequin ichthyosis 829
Immunodeficiencies 830
Birthmarks, congenital tumours and other naevoid conditions 830
Pigmented birthmarks 830
Congenital melanocytic naevi 830
Naevoid pigmentary disorders 830
Mongolian spots 830
Naevus of Ota 830
Epidermal naevi 830
Vascular birthmarks 831
Some congenital tumours 833
Vascular tumours 833
Kasabach–Merritt syndrome 833
Langerhans cell histiocytosis 833
Congenital leukaemia 833
Sarcomas 833
Congenital neuroblastoma 833
Infantile myofibromatosis 833
Juvenile xanthogranuloma 834
Dermoid cysts 834
Encephalocele, meningocele and heterotopic brain tissue 834
Aplasia cutis 834
Gluteal granulomas 834
Introduction
There are important differences between the skin of the neonate, in particular the preterm neonate, and that of the child or adult, and an understanding of those differences is vital to the appropriate care of the baby.
Some skin disorders are very specific to the neonatal period. These are mostly benign and transient and their main importance is the fact that they can imitate more serious disorders. Cutaneous infections in the neonate are almost all potentially serious and may have atypical presentations; the first sign of certain systemic infections can be cutaneous. Some important systemic disorders present in the neonatal period with skin signs. Most naevi are present at birth and a number of skin tumours can be congenital or appear in the neonatal period. Finally, several important ongoing skin diseases may manifest in the first month of life. The recognition of these patterns of disease is important so that appropriate investigations and intervention can be instituted and so that the parents can be reassured or offered a realistic prognosis.
Structure and function of the neonatal skin
By 24 weeks’ gestation, the anatomy of the skin is essentially similar to that of the older individual, but it is some years before functional maturity is achieved.
The epidermis of the baby is fragile ( ), especially in preterm neonates, with a susceptibility to fissuring and an increased risk of injury from adhesives, chemical burns from alcohol swabs and disinfectant solutions ( ) and thermal burns from transcutaneous oxygen monitors ( ).
Compared with that of the older child, there is an increased permeability of neonatal skin, especially in the preterm baby ( ). This increases the risk of toxic effects of the application of agents such as iodine, hexachlorophene, gammabenzene hexachloride and phenol, and possibly some of the myriad over-the-counter preparations which are applied to the skin of babies. The absorption of topical steroid preparations is much increased, leading to potential side-effects, both local and systemic. This tendency to complications from the use of applied agents is exaggerated by the large surface area to bodyweight ratio of the baby.
Vasomotor instability is characteristic in the neonate and is responsible for certain essentially benign and physiological, but clinically striking, entities. A rubor or generalised redness is often present in the early hours of life. Peripheral acrocyanosis presents as a bilaterally symmetrical, intermittent, blue discoloration of the hands and feet, which usually disappears after the early weeks. Harlequin colour change is a vascular phenomenon probably caused by an immature autonomic regulatory mechanism ( ; ). When the neonate is lying on one side, the lower half of the body is red and the upper half is pale, with a clear midline separation. This colour change reverses on altering the baby’s position. It is a very transient phenomenon and does not indicate any significant neural or vascular abnormality. Physiological cutis marmorata or livedo reticularis is a benign transient blue or purple cutaneous mottling, most marked when the baby is cool, lasting minutes to hours but reversing quickly on warming ( ). The tendency to the condition lasts for weeks or months.
However, livedo is not always physiological ( Box 32.1 ). A more persistent livedo may be seen in a number of syndromes, in congenital hypothyroidism and rarely in neonatal lupus. A very striking segmental livedo, associated with dilated veins and, sometimes, cutaneous atrophy, is a feature of cutis marmorata telangiectatica congenita, a rare vascular malformation.
Physiological cutis marmorata
Down syndrome
Trisomy 18
Homocystinuria
Cornelia de Lange syndrome
Neonatal lupus erythematosus
Congenital hypothyroidism
Cutis marmorata telangiectatica congenita
Macrocephaly–cutis marmorata syndrome
Neonatal skin often manifests the same type of hyperpigmentation as is seen in pregnancy. This is believed to be due to the influence of maternal and placental hormones as part of the ‘minipuberty’ of the newborn. It affects particularly the external genitalia, and the linea alba is instead a linea nigra ( ).
Lanugo is the fine silky hair found to cover neonates, especially preterm babies. It is most marked on the shoulders, back and cheeks. It is usually shed within 3 months. There is an extremely rare inherited disorder, congenital hypertrichosis lanuginosa, characterised by a very profuse and persistent, widespread covering of lanugo hair ( ). There are a number of causes of neonatal hypertrichosis featuring an excess of either vellus hair (normal childhood non-scalp hair) or terminal hair (adult or scalp-type hair). While this may occur alone, it is usually part of a syndrome with other diagnostic features. Certain drugs may cause a neonatal hypertrichosis. Some of these conditions are listed in Box 32.2 .
Physiological lanugo hair
Congenital hypertrichosis lanuginosa
Primary isolated hypertrichosis
Hypertrichosis as part of various syndromes
Hypertrichosis with gingival fibromatosis
Congenital erythropoietic porphyria
Familial porphyria cutanea tarda
Cornelia de Lange syndrome
Coffin–Siris syndrome
Cantu syndrome
Leprechaunism
Seip–Berardinelli syndrome
Rubenstein–Taybi syndrome
Some mucopolysaccharidoses
Drug-induced hypertrichosis
Diazoxide
Fetal alcohol syndrome
Maternal minoxidil
Scalp hair may be sparse or abundant at birth. A well-defined patch of alopecia commonly develops in the occipital area. This is not, as commonly believed, due to rubbing the back of the head on the bedding surface. It is explained by understanding the fetal and neonatal hair cycles ( ). By 20 weeks’ gestation, there are well-developed hair follicles containing anagen (growing) hairs all over the scalp. Although the hair roots enter telogen (the resting stage, which lasts 10–12 weeks before the hairs inevitably fall) in a progressive manner from frontal to parietal areas at 26–28 weeks’ gestation, those in the occipital area remain in anagen until birth, when they abruptly enter telogen. These hairs fall at 9–12 weeks of postnatal life. In some babies large numbers of hairs in the parietal area are still in telogen at birth and a more extensive postnatal alopecia occurs, with hair remaining only at the vertex.
Pustules, blisters and erosions in the neonate
There are a large number of conditions, some transient and benign and others serious, which present with pustules, blisters or erosions. Some of these are listed in Boxes 32.3 and 32.4 .
Toxic erythema of the newborn
Transient neonatal pustular dermatosis
Infantile acropustulosis
Eosinophilic pustulosis
Pustular miliaria
Neonatal cephalic pustulosis and neonatal acne
Varicella
Herpes simplex
Staphylococcal impetigo
Streptococcal impetigo
Candida
Scabies
Incontinentia pigmenti
Hyper-IgE syndrome
Myeloproliferative disorder in Down syndrome
Sucking blisters
Herpes simplex
Varicella
Staphylococcal infections
Impetigo
Staphylococcal scalded-skin syndrome
Scabies
Aspergillus
Candida
Syphilis
Epidermolysis bullosa
Contact irritant dermatitis, chemical burn
Mastocytosis
Bullous ichthyosis
Incontinentia pigmenti
Neonatal pemphigus
Neonatal herpes gestationis
Congenital erosive and vesicular dermatosis
Zinc deficiency
Langerhans cell histiocytosis
Porphyrias
Congenital erythropoietic porphyria
Erythropoietic protoporphyria
Transient porphyrinaemia in Rh incompatibility
Benign transient neonatal disorders presenting with sterile pustules
There are many benign conditions that may present in the neonatal period with sterile pustules (see Box 32.3 ), which can mimic serious infections ( ; ).
Toxic erythema of the newborn
This is a self-limiting, benign, idiopathic condition, which occurs in about two-thirds of all neonates ( ) but almost never in premature babies. The onset is usually between 24 and 48 hours, but may occur at any time from birth to 14 days. The characteristic lesions are poorly demarcated erythematous macules, often surmounted by central pale papules, but occasionally pustules develop. The lesions may occur anywhere on the body surface apart from palms and soles, particularly on the face and trunk. When cases present at birth, lesions are more acrally distributed and are more often pustular. Smears taken from pustules and stained with Wright or Giemsa stain demonstrate numerous eosinophils and a peripheral blood eosinophilia is present. The disorder rarely lasts more than a few days.
Transient neonatal pustular dermatosis (transient neonatal pustular melanosis)
This condition presents at birth or in the first hours of life as lesions which quickly evolve from blisters to large flaccid pustules ( Fig. 32.1 ) ( ; ). These lesions occur mainly on the trunk and buttocks, but may be widespread. Over the next 1–2 days, the pustules rupture, with the formation of a peripheral collarette of scale, which separates after a further day or so to leave either normal skin or, in dark-skinned individuals, a temporary postinflammatory hyperpigmentation. Because the pigmentation depends on the skin colour, the term dermatosis is preferred to the earlier term melanosis. Occasionally, a few further crops of lesions appear. The pustules, which can closely simulate infective conditions, contain numerous neutrophils but are sterile on culture. The condition is entirely benign and does not require treatment; the prognosis is excellent.
Infantile acropustulosis
This is another benign idiopathic condition which commences in the neonatal period or early infancy ( ; ). Recurrent crops of extremely pruritic 2–4-mm vesicopustules develop on the hands and feet, especially on palmar and plantar surfaces ( Fig. 32.2 ) ( ). Initially, each crop lasts 7–14 days and recurrences occur at 2–3-week intervals. With time, the duration of each attack becomes shorter and the time between attacks longer, until the condition resolves spontaneously after many months. Cultures of the pustules are sterile. A clinically identical condition occurs as a postscabetic reaction following successful treatment of severe neonatal or infantile scabies. When reports of infantile acropustulosis are studied, it becomes clear that almost all of the patients have been treated for scabies ( ) and the existence of the condition as a distinct entity unrelated to scabies is in some doubt. The duration of the episode may be shortened with the use of strong topical steroids for a few days.
Eosinophilic pustulosis (eosinophilic pustular folliculitis)
This is a rare condition in which recurrent groups of sterile pustules, centred around hair follicles, develop on the scalp in the first few months of life ( ; ). Lesions begin as small, closely grouped red papules which quickly develop into pustules and then form crusted lesions which heal over several days ( Fig. 32.3 ). Several groups may occur at one time on the scalp. The lesions are characteristically very itchy. Occasionally there are a few follicular lesions at other sites, and, in older infants, follicular and non-follicular lesions away from the scalp become more prominent. Cropping of lesions may continue for many months before there is eventual spontaneous resolution of the condition. Smears from the pustules show variable proportions of neutrophils and eosinophils and no evidence of infection on culture. There is often a peripheral blood eosinophilia present at the time of onset of new lesions. The use of fairly potent topical steroids may shorten the duration of each episode a little but has no effect on the overall course of the condition.
Miliaria
This is a sweat retention condition common in young babies and which is important to differentiate from milia (p. 827) ( ). An obstruction, the nature of which is unknown, develops in the intraepidermal part of the sweat duct and sweat is trapped. The duct may rupture and sweat then leaks into the surrounding epidermis. Lesions begin as small red macules, soon surmounted by red papules (miliaria rubra) or pustules (pustular miliaria) ( Fig. 32.4 ). Unlike miliaria in older individuals, the condition in infancy often occurs in the absence of fever or significant external occlusion of the skin. Lesions occur mainly on the face, scalp and upper trunk. There is often a mixture of red and pustular lesions, and the distribution and severity of the condition characteristically vary considerably from day to day or even within the same day. It is noted to be worse in areas of occlusion, such as where the face has been against the breast, and also at times of increased heat. It is important to stress to the parents that this is a benign phenomenon over which they have little control and which, if anything, will be worsened by the application of topical agents.
Neonatal cephalic pustulosis and neonatal acne
Both of these terms are used to describe a condition presenting within the first 3–4 weeks of life with erythematous papules and pustules but no comedones, occurring primarily on the cheeks but scattered elsewhere on the face and extending to the scalp and resolving after several more weeks ( ; ). The condition is quite separate from infantile acne, which is predominantly comedonal, occurs almost entirely in boys and rarely presents before 3 months of age. There is an opinion that the term neonatal acne should be abandoned in favour of neonatal cephalic pustulosis ( ). There is a suggestion that the lesions of cephalic pustulosis may be an inflammatory reaction to Malassezia species, but these are found as commensals on neonatal skin, so their pathogenic role is difficult to assess ( ). It is doubtful whether antifungal treatment significantly shortens the duration of this self-limiting condition. This condition is clinically very similar to pustular miliaria, and only biopsy, which clearly would be unjustified, could differentiate them in some cases.
Infective conditions presenting with pustules, blisters or erosions
A variety of infections can present in the neonatal period with pustules (see Box 32.3 ), blisters (see Box 32.4 ) or erosions. Some present predominantly with one or other type of lesion, but some infections can produce all types. Most of these conditions are described in more detail in Chapter 39, part 2 and only the cutaneous presentations are described here.
Varicella
Because the infection in the neonate is usually severe, there may be many lesions in the same stage of development. Hence, the condition may present as a widespread vesicular or pustular disorder with a wide differential diagnosis ( ). It may not be recognised clinically as varicella until the characteristic crusts form several days later. Congenital varicella may present as erosions but often stellate scarring is already present at birth.
Herpes simplex
The skin lesions are grouped blisters, localised initially on the presenting part, usually the head, with the onset typically between the fourth and eighth days of life ( ). They are often localised in the sites of application of scalp electrodes during delivery. Sometimes the lesions become pustular ( Fig. 32.5 ), but they soon burst to form erosions, which may be deep and haemorrhagic. A characteristic pattern is individual lesions a few millimetres across coalescing to produce larger erosions with a geographical shape or scalloped border. On the thick skin of the palms or soles, the blisters or pustules may remain intact, producing a more confusing clinical picture. The diagnosis can be confirmed by electron microscopy (EM) of vesicle fluid. Treatment with intravenous aciclovir is urgent ( Ch. 39 ).
Impetigo
This is usually a staphylococcal bullous impetigo, originating in an infected umbilical wound. The lesions first appear as intact vesicles, then become intact pustules, which eventually rupture to form fast-spreading erosions which, being very superficial, quickly dry out to form shiny crusts. Occasionally group A streptococcal infections present as pustules, but a non-specific omphalitis is more common. Systemic antibiotics are required.
Staphylococcal scalded-skin syndrome
The condition commences with a macular erythema, initially on the face and in the major flexures and then becoming generalised. The skin is exquisitely tender. After 2 days, flaccid bullae develop and the skin wrinkles and shears off ( Fig. 32.6 ). The exfoliation is most marked in the groin, neck fold and around the mouth and may involve the entire body surface, but mucosae remain uninvolved. The child is usually febrile but, because of the superficial level of the split, fluid loss is rarely significant. The erosions crust and dry and heal with desquamation over 4–8 days leaving no sequelae. Cultures from affected skin and blister fluid are usually negative. The usual source in a neonate is an infected umbilical stump. The condition responds quickly to intravenous antistaphylococcal antibiotics.
Candida
In congenital candidiasis, the infection is acquired in utero and presents in the first 2 days of life with a diffuse eruption of papules, papulovesicles and pustules, often on an erythematous base ( Fig. 32.7 ) ( ). These usually settle in a few days with superficial desquamation.
In neonatal candidiasis, the infection is contracted during passage through an infected birth canal and there are several different presentations depending on the maturity and status of the neonate.
Localised neonatal candidiasis
This includes oral thrush and Candida napkin dermatitis ( ). The latter demonstrates a beefy-red erythema extending a variable distance from the groin folds, with a thick white accumulation deep in the fold. There are often satellite pustules which rupture to form a peripheral scale.
Invasive fungal dermatitis
This is a term used to describe primary cutaneous, erosive, crusted, sometimes necrotic lesions occurring in very-low-birthweight (VLBW) infants ( ). A similar condition can occur with other fungal infections, including Aspergillus .
Cutaneous lesions of systemic candidiasis
VLBW infants with systemic candidiasis can present with an extensive burn-like dermatitis followed by peeling ( ).
Scabies
Clinical manifestations of scabies have been reported as early as the second week of life ( ). The lesions in neonatal scabies, which include papules, nodules, vesicles and pustules, tend to be very widespread, often with facial and scalp involvement, which is rare in older infants. Vesicles or pustules on the palms and soles are common features. Secondary eczematisation and infection may complicate the clinical picture. Permethrin 5% cream is regarded as safe at any age, except possibly in the VLBW infant. Nodules frequently persist, and even become more numerous, for some weeks, even after successful treatment. A common postscabetic phenomenon is recurrent episodes of pustules on the palms and soles, clinically identical to the condition designated infantile acropustulosis.
Syphilis
While macular or maculopapular eruptions are more frequently seen, neonates with congenital syphilis may present with vesicles, bullae and erosions ( ). Blisters form on an erythematous base and rupture easily, leaving a macerated area, sometimes with a peripheral annular scale. Haemorrhagic bullae on the palms and soles are particularly suggestive of syphilis.
Dermatological conditions presenting with pustules, blisters or erosions (see Boxes 32.3 and 32.4 )
Epidermolysis bullosa
This is a group of diseases characterised by trauma-induced blistering of skin ( Fig. 32.8 ) and mucosae ( ; ). There are over 15 types now identified, separated on the basis of inheritance, clinical features and EM identification of the cleavage plane of the blister: within the epidermis, between the epidermis and dermis, or in the upper dermis. Blisters are clear or filled with serosanguineous material, depending on their level. They may rupture or spontaneously subside. Secondary bacterial infection is common. Milia are small retention cysts resulting from a split through pilosebaceous or sweat ducts; these eventually extrude. Permanent scarring is mainly a feature of the forms with a deeper level of split and varies from mild, with minor cosmetic significance, to severe, with gross deformity and functional disability. Sometimes epidermolysis bullosa presents with extensive areas of denuded skin, particularly on the legs, as well as blistering; some of these cases may be associated with pyloric atresia ( ). A firm diagnosis and typing should always be established as soon as possible. The diagnostic techniques include EM, immunofluorescent microscopy using antibodies to antigens known to be affected in EB and mutation analysis on DNA extracted from the blood of the patient and his or her family. This enables a prognosis to be given and a management plan to be established for the present and future.
