Erythema Toxicum Neonatorum Clinical Presentation
- Author: Neil F Gibbs, MD; Chief Editor: Dirk M Elston, MD more...
History
When evaluating for erythema toxicum neonatorum (ETN), focus the history on age at onset of the eruption, absence of systemic signs (eg, fever, irritability, lethargy, mucocutaneous involvement), or maternal history of herpes simplex/varicella viral infection, bacterial pyoderma, or candidiasis.[13]
- Infants with erythema toxicum neonatorum otherwise are healthy and lack systemic symptoms.
- The eruption is self-limited with most cases resolving within 5-14 days without residual sequelae.
- Recurrences are uncommon but have been reported up to the sixth week of life. They tend to be mild in severity.
Physical
Focus the physical examination on location, size, and distribution of macules, wheals, papules, and pustules on the skin. Note the absence of mucosal, palmar, or plantar involvement. Signs of systemic toxicity, including hypothermia or hyperthermia, lethargy, and irritability, are not associated with erythema toxicum neonatorum.
- Erythema toxicum neonatorum most commonly presents with a blotchy, evanescent, macular erythema, often on the face or trunk.
- The macules are irregular, blanchable, and vary in size.
- In more severe cases, pale yellow or white wheals or papules on an erythematous base may follow. In approximately 10% of patients, 2-4 mm pustules develop.
- Numbers and distribution of lesions vary from a few and widely scattered to numerous and extensive.
- Sites of predilection include the forehead, face, trunk, and proximal extremities, but lesions may occur anywhere, including the genitalia.[14] Involvement of the mucous membranes and palms and soles rarely occurs.
Causes
The cause of erythema toxicum neonatorum is unknown. Multiple theories have been proposed to explain this common disorder.
- Neonates have an increased number of hair follicles compared with adults, and the occurrence of erythema toxicum neonatorum in non–hair-bearing areas such as palms and soles is rare. Inflammatory cells tend to concentrate around hair follicles, and coccilike microbes have been demonstrated in the follicular epithelium and inside the inflammatory cells. This suggests that erythema toxicum neonatorum may be a response to microbes that have penetrated the hair follicle. This process may possibly be integral in developing the new immune system.[15]
- The high frequency of eosinophilia suggests an allergic basis, leading some authors to suggest that erythema toxicum neonatorum may be an immediate hypersensitivity reaction to a substance passed from the mother transplacentally; however, convincing support is lacking for this theory.[16]
- No responsible exotoxin, allergen, component of sebum, or infectious agent has been linked credibly to erythema toxicum neonatorum.
- Medications administered to newborns and the mode of feeding have no effect on incidence.
- Other proposed theories include a transient adjustment reaction of the skin to mechanical or thermal stimulation or an acute graft-versus-host reaction induced by the maternal-fetal transfer of lymphocytes before or during delivery.[17] Analysis of skin samples of 2 male patients with erythema toxicum neonatorum did not support a graft-versus-host reaction because no maternal cells were found in the samples using fluorescence in situ hybridization identification of cells with 2 XX chromosomes.[18]
- Risk factors include birth in hot wet climates, being fed on a mixed diet or milk-powder substitute, and being born via vaginal delivery. A positive correlation has been recognized between the length of labor and both the incidence of erythema toxicum neonatorum and the duration of the cutaneous manifestations.[8]
Schwartz RA, Janniger CK. Erythema toxicum neonatorum. Cutis. Aug 1996;58(2):153-5. [Medline].
Marchini G, Hultenby K, Nelson A, et al. Increased expression of HMGB-1 in the skin lesions of erythema toxicum. Pediatr Dermatol. Sep-Oct 2007;24(5):474-82. [Medline].
Marchini G, Lindow S, Brismar H, et al. The newborn infant is protected by an innate antimicrobial barrier: peptide antibiotics are present in the skin and vernix caseosa. Br J Dermatol. Dec 2002;147(6):1127-34. [Medline].
Marchini G, Stabi B, Kankes K, Lonne-Rahm S, Ostergaard M, Nielsen S. AQP1 and AQP3, psoriasin, and nitric oxide synthases 1-3 are inflammatory mediators in erythema toxicum neonatorum. Pediatr Dermatol. Sep-Oct 2003;20(5):377-84. [Medline].
Nelson A, Ulfgren AK, Edner J, Stabi B, Brismar H, Hultenby K. Urticaria Neonatorum: accumulation of tryptase-expressing mast cells in the skin lesions of newborns with Erythema Toxicum. Pediatr Allergy Immunol. Dec 2007;18(8):652-8. [Medline].
Carr JA, Hodgman JE, Freedman RI, Levan NE. Relationship between toxic erythema and infant maturity. Am J Dis Child. Aug 1966;112(2):129-34. [Medline].
Singh M, Arora NK, Sroa HS. Urticaria neonatorum--an earliest marker of atopy. Indian J Med Res. Feb 1980;71:273-7. [Medline].
Liu C, Feng J, Qu R, et al. Epidemiologic study of the predisposing factors in erythema toxicum neonatorum. Dermatology. 2005;210(4):269-72. [Medline].
Levy HL, Cothran F. Erythema toxicum neonatorum present at birth. Am J Dis Child. Apr 1962;103:617-9. [Medline].
Marino LJ. Toxic erythema present at birth. Arch Dermatol. Oct 1965;92(4):402-3. [Medline].
Akoglu G, Ersoy Evans S, Akca T, Sahin S. An unusual presentation of erythema toxicum neonatorum: delayed onset in a preterm infant. Pediatr Dermatol. May-Jun 2006;23(3):301-2. [Medline].
Chang MW, Jiang SB, Orlow SJ. Atypical erythema toxicum neonatorum of delayed onset in a term infant. Pediatr Dermatol. Mar-Apr 1999;16(2):137-41. [Medline].
Monteagudo B, Labandeira J, Cabanillas M, Acevedo A, Toribio J. Prospective Study of Erythema Toxicum Neonatorum: Epidemiology and Predisposing Factors. Pediatr Dermatol. Nov 8 2011;[Medline].
Maffei FA, Michaels MG, Wald ER. An unusual presentation of erythema toxicum scrotal pustules present at birth. Arch Pediatr Adolesc Med. Jun 1996;150(6):649-50. [Medline].
Marchini G, Nelson A, Edner J, Lonne-Rahm S, Stavreus-Evers A, Hultenby K. Erythema toxicum neonatorum is an innate immune response to commensal microbes penetrated into the skin of the newborn infant. Pediatr Res. Sep 2005;58(3):613-6. [Medline].
Keitel HG, Yadav V. Etiology of toxic erythema. Erythema toxicum neonatorum. Am J Dis Child. Sep 1963;106:306-9. [Medline].
Bassukas ID. Is erythema toxicum neonatorum a mild self-limited acute cutaneous graft-versus-host-reaction from maternal-to-fetal lymphocyte transfer?. Med Hypotheses. Aug 1992;38(4):334-8. [Medline].
Droitcourt C, Khosrotehran K, Halaby E, Aractingi S. Maternal cells are not responsible [corrected] for erythema toxicum neonatorum [corrected]. Pediatr Dermatol. May-Jun 2008;25(3):411-3. [Medline].
Ferrandiz C, Coroleu W, Ribera M, Lorenzo JC, Natal A. Sterile transient neonatal pustulosis is a precocious form of erythema toxicum neonatorum. Dermatology. 1992;185(1):18-22. [Medline].
Van Praag MC, Van Rooij RW, Folkers E, Spritzer R, Menke HE, Oranje AP. Diagnosis and treatment of pustular disorders in the neonate. Pediatr Dermatol. Mar-Apr 1997;14(2):131-43. [Medline].
Freeman RG, Spiller R, Knox JM. Histopathology of erythema toxicum neonatorum. Arch Dermatol. Oct 1960;82:586-9. [Medline].
Luders D. Histologic observations in erythema toxicum neonatorum. Pediatrics. Aug 1960;26:219-24. [Medline].
Marchini G, Ulfgren AK, Lore K, Stabi B, Berggren V, Lonne-Rahm S. Erythema toxicum neonatorum: an immunohistochemical analysis. Pediatr Dermatol. May-Jun 2001;18(3):177-87. [Medline].

