Introduction

Evidence shows Transient Neonatal Pustular Melanosis (TNPM) is benign and not an infection; the pustules can last up to 2 days and can resolve without any intervention. Despite its non-infectious nature, TNPM can very rarely cause secondary infections in the neonate.¹

This article will explore the rare but possible secondary infections that can occur in neonates affected by TNPM. Starting by understanding the disorder, its complications, the rarely occurring secondary infections, how they are diagnosed and differentiated from TNPM, and how to manage and treat them.

What is transient neonatal pustular melanosis?

TNPM presents right after birth in the form of lesions on the neonate’s skin. The lesions can last up to 2 days and can appear on any body part, including palms and soles of the feet. These lesions are asymptomatic and can be categorised as follows:²

• Vesiculopustular which are small and superficial pustules without surrounding redness or signs of infection on the surrounding skin
• A collarette of scales and flaky skin on the edge of the lesions that appear after the pustules have burst
• Hyperpigmented macules that are flat dark spots on the skin, left after the collarette and scales resolve

All of these are non-infectious and do not cause any itchiness or harm to the skin. 

Pathophysiology

Researchers have yet to find the cause of these pustules. However, evidence shows that they form below the surface of the baby’s skin and are filled with fluid that contains white blood cells. These cells are meant to fight infections, but there are no bacteria, fungi, or viruses in these pustules, which makes them completely harmless.³

Despite the non-infectious nature of TNPM, environmental factors are still great contributors to secondary infections. These factors and the undeveloped nature of the barrier function of the neonate’s skin can act as a catalyst for any potential secondary infections.

Complications of TNPM

TNPM typically has no systemic symptoms; it is not a complicated disorder, but bacterial infections can occur if the lesions are disrupted or inadequately managed. Very rarely, these infections occur through exposure to bacteria.

This is why as healthcare professionals, guardians, or parents, it must be kept in mind the significance of maintenance when it comes to TNPM. Ensuring that these lesions are well managed during the small period they are on the neonate’s skin.

Rarely occurring secondary infections

A secondary infection normally involves the colonisation of TNPM lesions by any pathogenic bacteria. This can lead to inflammation on the neonate’s skin and potential systemic involvement that can affect the entire body instead of just the skin when the origin of the infection is set.⁴

TNPM, when not supervised and treated as it should be, could evolve to become life-threatening to the neonate. This can look like a Staph aureus, streptococcus, viral infections like herpes simplex and varicella, or fungal infections such as candidiasis.⁵

These infections can be caused by various factors, including leaving aside the compromised skin, the hospital environment and germs in the hospital could contribute to the infections. The people around the neonate, while their skin is compromised, if not well-sanitised, their clothes and hands could transfer infection to the neonate.

As parents, caregivers, and healthcare professionals, it is vital to be vigilant and ensure we are actively caring for the safety of the infant. Despite being self-limiting, this disorder cannot be neglected by reducing our attention to external contaminants

Differential diagnosis

Despite previous publications, a TNPM diagnosis is not always difficult to make. This disorder looks like skin bumps on the neonate’s skin called pustules, which are pus-filled without any surrounding redness. They leave behind dark, pigmented spots that fade over time.²

At the onset of a secondary infection, the pustules may look different; they may have some increased redness around and on the pustules, a warmth to the skin surrounding the pustules, pain, swelling, and some discharge (such as pus) from the affected areas. Itching may significantly increase, and there could be signs of a fever due to the infection. To make sure that the right diagnosis is made on these secondary infections, the following tools are to be used:

• Clinical examination¹
  • After the normal method of TNPM diagnosis is performed, new symptoms start to arise. One needs to look at the surrounding skin and, if any erythema is noted, it could be a sign of a secondary infection.
• Laboratory tests⁵
  • Healthcare professionals should investigate the neonate’s peripheral blood count to eliminate any systemic infections and have a clear look at the health of the neonate.
  • Blood film and culture are needed to identify any underlying viral and or bacterial infections
  • A pustular fluid gram staining, microscopy, and culture to be able to differentiate between TNPM and any other bacterial or fungal infections
  • To detect any viral infections, like herpes simplex, a viral PCR test should be done
• Skin biopsy³
  • When there is suspicion of secondary infections, employing a skin biopsy test is essential. This can show subcorneal or intraepidermal pustules with any predominance of neutrophils that aids in differentiating TNPM from other conditions, such as erythema toxicum neonatorum.

Management and treatment

There is no standard care for TNPM due to its self-limiting and benign nature, but when secondary infections appear to be manifesting, management and treatment should be taken a step further.

This could be in the form of topical fungal creams if fungal infection is diagnosed, prescribing antibiotics to the neonate if bacterial infections is diagnosed, and many others.  When the pustules rupture, proper wound care should be administered to keep the surrounding area clean to prevent any spread of infection. Use of an antibacterial skin cleanser for the neonate to ensure no more irritation occurs on the skin.

Follow-up and monitoring is very important in this stage to ensure there is little to no progression of the secondary infection. If there is progression, it can lead to a lot more infection and systemic issues in the neonate.¹

Ensure the environment the infant is in is clean, and the people who are interacting with the neonate are clean and disinfected as well. Keep a close eye on any changes in the neonate’s symptoms and adjust treatment as needed.

Conclusion

It is very important to monitor your neonate patient or your baby when they are affected by TNPM, especially if the environment you are in is not at its best. Despite its benign and self-limiting nature, TNPM can still advance to secondary infection if the neonate is not well taken care of. These secondary infections can range from Staph aureus, Streptococcus, to viral and fungal infections that can be detrimental to the neonate’s life if not well managed.

An early secondary infection diagnosis could be what aids in quick recovery for the infant; this is why monitoring of the skin is emphasised. Various ways for diagnosis can be employed, such as biopsies and laboratory tests.

More research is still needed on this disorder and the secondary infections that could affect it. Despite the little knowledge we have, we need to be vigilant. 

Summary

TNPM is benign and not a true infection and has no systemic symptoms. It lasts just a couple of days and leaves behind scars that can last up to a couple of weeks. This disorder is self-limiting, meaning it goes away without any intervention. Despite this, when not monitored and well taken care of it can advance to a secondary infection. This can be due to the hospital environment or the people the neonate interacts with on a daily basis. Nonetheless, these infections deserve immediate intervention as they can cause various systemic issues in the neonate.

These infections can range from bacterial to fungal to viral. A differential diagnosis is needed to ensure the right diagnosis is made, and as healthcare professionals, you are not treating the wrong infections. All in all, it is essential to be vigilant when dealing with TNPM to ensure the problem does not escalate.