Erythema toxicum neonatorum usually appears after the age of 3 days and within the first two weeks of life, but they may rarely occur slightly before or later [1] [2]. Manifestations consist of macular erythema, papules, pustules, and vesicles. Particular skin changes resolve by themselves in several minutes to hours, leaving no sequelae [3]. As old lesions disappear, new ones appear and the total duration of erythema toxicum neonatorum is from five days to two weeks. The patient is not febrile during this period and signs such as lethargy or irritability are absent. Mucosal involvement is almost always absent and, when present, the physician should consider herpes simplex infection or candidiasis, especially if present in the mother [4]. Once the disease is resolved, recurrence is infrequent but mild episodes are possible before the sixth week of life.

The skin lesions with an erythematous halo spread centripetally. They are usually absent in the palmar and plantar areas while the lesions are most often found on the face [5], trunk, proximal limbs, and buttocks but may even involve the genitalia [6]. Their size is variable, they are blanchable, and have irregular margins.

Caucasian infants born after a long labor by vaginal delivery, who have a higher birth weight and are born at a higher gestational age are more likely to develop erythema toxicum neonatorum and manifestations tend to have a longer duration. Newborns that receive infant formulas, those born in the summer or autumn whose mothers are younger than 30 years are also at a higher risk [7].

Clinical examination and attentive history inquiry are key tools for erythema toxicum neonatorum diagnosis and further investigations are usually unnecessary. A complete blood count may reveal increased eosinophil numbers. The histological evaluation of intralesional content shows the presence of eosinophils and neutrophils [4] [8]. If eosinophils are absent or a systemic disease is suspected, bacterial, viral, and fungal cultures are required. A potassium hydroxide preparation may confirm or exclude candidiasis. If cultures are proven negative and doubt still persists, a skin biopsy should be performed. In the case of erythema toxicum neonatorum, this method will highlight the presence of dermal edema and perivascular inflammatory infiltrate. The root sheath of the hair follicle may also be invaded by eosinophils while pustules are filled with the eosinophil-rich material [9]. In a severely ill child, blood cultures are indicated in order to exclude sepsis. Herpes virus infection can also be ruled out using fluorescent antibody testing or a Tzanck preparation.

No treatment is necessary for ETN, as it is a self-limiting condition. The rash will resolve on its own, usually within a week or two. Parents and caregivers are advised to keep the baby's skin clean and dry, but no special creams or medications are required.

The prognosis for infants with ETN is excellent. The condition is benign and does not cause any long-term health issues. The rash will disappear without leaving any scars or marks. There are no known complications associated with ETN.

The exact cause of ETN is unknown. It is thought to be a normal physiological response of the newborn's skin as it adapts to the external environment after birth. It is not caused by an infection or an allergic reaction.

ETN is a common condition, affecting up to 50% of full-term newborns. It is less common in premature infants. There is no known preference for gender or ethnicity, and it can occur in any newborn regardless of their background.

The pathophysiology of ETN is not fully understood. It is believed to involve the immune system's response to the new environment outside the womb. The rash is composed of eosinophils, a type of white blood cell, which suggests an immune-mediated process.

There are no known methods to prevent ETN, as it is a natural and benign condition. It is not related to hygiene or environmental factors, and it is not contagious. Parents should be reassured that ETN is a normal part of some newborns' development.

Erythema Toxicum Neonatorum is a common, harmless skin condition in newborns characterized by a rash of red spots with yellow or white centers. It appears within the first few days of life and resolves on its own without treatment. The condition is not harmful and does not lead to any long-term health issues.

For parents and caregivers, it is important to know that ETN is a normal and temporary condition. The rash may look concerning, but it does not cause discomfort to the baby and will go away on its own. No special treatment is needed, and the baby's overall health is not affected. If you have any concerns about your newborn's skin or health, consult with your healthcare provider for reassurance and guidance.

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9. Marchini G, Ulfgren AK, Lore K, et al. Erythema toxicum neonatorum: an immunohistochemical analysis. Pediatr Dermatol. 2001;18(3):177-187.