Independent nurse prescriber Louise Walsh provides insight into the different types of milia and shares methods of treatment and prevention
What is milia and how does it form?
There are commonly two types of milia; primary and secondary. Primary milia comprises benign, keratin-filled cysts, derived from the pilosebaceous follicle, seen just under the skin’s surface,1 whereas secondary milia is an inflammatory condition characterised by plaques of milia.2,3,4 In children and adults (both men and women), they usually arise around the eye and on the cheeks; there is no evidence to explain exactly why these areas are affected more than others, but it may be because the skin is often thinner in these locations.5 Primary milia is frequently seen in infants, typically referred to as milk spots which often resolves itself. However, milia seen in adults is usually chronic; the evidence for why is unknown. It can be regarded as unsightly for some individuals and is difficult to cover with make-up due to its bumpy effect. The cause of milia in infants is also unclear, however there is some research that suggests milia in adults is caused initially by skin damage and/or the use of products with mineral oil and lanolin ingredients, such as emollients. It potentially arises because the skin is unable to absorb the product and there is a build-up within the follicle over time.6
It is not uncommon to see milia in aesthetic clinics as, nowadays, patients are frequently seeking skin rejuvenation treatments and may be conscious of this condition. Often, patients will have tried to treat their milia like regular breakouts but quickly learn that it isn’t as easily resolved. In this article, I discuss the typical clinical presentations and how to treat and prevent milia.
Clinical presentation and diagnosis
On physical assessment, primary milia is firm, sub-dermal, uniform, pearly white to yellowish, with domed lesions usually measuring 1-3mm in diameter. The lesions are asymptomatic, non-itchy and commonly develop on the face, particularly around the eyes. It is common to see a single milia, as well as groups of 3-10 milium.5
No investigations are needed for the diagnosis of primary milia. The clinical appearance is diagnostic enough.6
Secondary milia manifests as distinct plaques such as in Figure 1; this is a rare inflammatory condition characterised by plaques of milia in the periauricular area.2,3,4
These plaques can develop following trauma to the skin, for example, after a burn, in a blistering disorder such as epidermolysis bullosa, following a resurfacing skin treatment and even after tattooing.7,8 Secondary milia has also been described following potent topical corticosteroid use.9 These are all thought to be a result from damage to the pilosebaceous unit.
Unlike primary milia (shown in Figure 2) which needs no further investigations, it is essential to investigate the underlying inflammatory condition that is present with secondary milia to address the initial problem to avoid secondary milia reoccurring.10
Multiple eruptive milia
Multiple eruptive milia is also a rare condition and is characterised by the sudden development of crops (patches) of milia over the course of weeks to months. If your patient has an acute history of milia it will need to be considered that they may be at risk of multiple eruptive milia.11,12 Eruptive milia can occur on the head, neck, and upper body.13 It is broken down into three categories:14,15
Spontaneous without a known cause or association (i.e. idiopathic)
A familial pattern with autosomal dominant transmission
A component of a genodermatoses. It is noted that only six cases of idiopathic multiple eruptive milia have been reported in the English literature.14,15
Both primary milia and multiple eruptive milia have been reported as familial disorders with autosomal dominant inheritance.16,17
Management of milia
Although milia is harmless and treatment is not necessary, when the milia does not resolve itself (as it often does in babies) there are a few treatment options for adults to consider, which are now commonly being offered within aesthetic clinics.
No topical or systemic medications are effective to treat primary and secondary milia, however single case reports have demonstrated the success of topical tretinoin.16
It is not uncommon to see milia in aesthetic clinics as, nowadays, patients are frequently seeking skin rejuvenation treatments and may be conscious of this condition
Deroofing is the most commonly-utilised technique where a sterile needle pierces the skin, then the milia is taken out with the blade of the needle. The milia can often be scooped out whole, as it is quite firm in texture. For a successful outcome, it is important to ensure the whole milium is removed. This procedure is fast and has minimal risks if an aseptic technique is followed. It typically leaves the patient with a small graze where the milia was, which should heal quickly.
Hyfrecation can be used to shatter and dehydrate the cyst.18 With this treatment option, a fine tip needle is used which delivers either an electric current or radiofrequency. This is usually only available in clinics where there is a dermatologist working within the team.
As well as this, cryotherapy is sometimes used to freeze the cyst; this can leave a small blister, which should resolve over a week or so. Secondary milia has also been treated effectively with electrodesiccation (the drying of tissue through the use of electrical current) or carbon dioxide laser (also known as co2 laser that uses short pulsed light energy).19-21
Risks and complications of treatment
When choosing an appropriate treatment method, it is vital to be confident and competent with the procedure and its associated risks and outcomes. Milia is often located near the eyes, which makes it a high-risk region to work on. It is important that you have a steady hand and your patient is reassured and unlikely to jump. Clearly detailing what is to come in your consultation process should help to prevent this. As with most treatments that compromise the skin, infection, bleeding and swelling are all potential risks. Scarring needs to be discussed thoroughly during the consultation process as some patients may prefer to keep the milia, rather than gain a possible scar.
The treatment options mentioned will cause discomfort and others may require local anaesthetic, (for the treatment of hyfrecation, for example) which then carries risks of allergic reactions.
None of the procedures can guarantee that the milia will be completely removed, although a good result is commonplace. It is also important to manage patients’ expectations as milia can return.
As milia can return, retinols (under guidance) and gentle skin peels are recommended to keep the skin soft and encourage cell renewal, if suitable for the patient’s skin-type and lifestyle.23 It is also good practice to remind patients to avoid skin products which contain mineral oils and lanolin to prevent the chances of reoccurrence.
Primary milia is completely harmless and very common. In our current times, our patients are more-often-than-not striving for immaculate unblemished skin, so the desire for milia to be removed is on the increase and having the skill to do so is a great asset to any practice.
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