Milia

Are You Confident of the Diagnosis?

Characteristic findings on physical examination

Milia are superficial benign keratinous cysts usually 3 mm or less with a uniform appearance (Figure 1). They may arise primarily or secondarily and are classified as such.

Figure 1.

Multiple small superficial 1-2 mm white papules.

Primary milia includes congenital, benign primary milia of children and adults, milia en plaque, eruptive, and genodermatosis-associated. Secondary milia may be disease associated, medication associated, or trauma associated.

Congenital milia occur in about half of newborns without racial or gender predilection and favor the face, scalp, and upper body. Oral inclusion cysts, firm translucent or white papules measuring 3 mm or less, may be present and include “Epstein’s pearls” on the gumline or “Bohn’s nodules” on the hard palate.

Benign primary milia of children and adults favors the cheeks and eyelids and tends to be more persistent. Pseudoacne of the nasal crease is observed in a subset of preadolescent patients and presents as a row of milia within the nasal crease.

Milia en plaque is a very rare entity and presents as numerous milia within an erythematous plaque several centimeters in diameter, usually on the head or neck. Lesions may be mistaken for nevus comedonicus, xanthelasma, Favre-Racouchot syndrome, or follicular mucinosis.

Eruptive milia refers to lesions that arise spontaneously in too large a number to be classified as benign primary milia of child/adulthood. Milia arise over weeks to months and favor the head and upper body. The reported age distribution is wide.

Milia may occur as a feature of many genodermatoses, including but not limited to, Bazex syndrome, Rombo syndrome, Brooke-Spiegler syndrome, oro-facial-digital syndrome, atrichia with papular lesions, pachyonychia congenita type II, basal cell nevus syndrome and KID syndrome. Milia occurring with epidermolysis bullosa and hereditary porphyrias are best considered as secondary milia.

Secondary milia are clinically identical to primary milia and may be found anywhere on the body, particularly in sites affected by the predisposing condition.

Diagnosis confirmation

The clinical differential diagnosis of milia is small. The clinical appearance is typically very characteristic and the diagnosis is easily made. Closed comedones, small 1mm felsh to yellow white papules can mimic milia. However milia typically are a starker white color. Fibrous papules should not give one much of a dilemmea in differentiating from a milia. They are usually larger papule, typically solitary on the nose. Can be multiple on the face, but are a flesh colored in nature.

Who is at Risk for Developing this Disease?

Milia are exceedingly common in the neonatal period, observed in nearly half of term newborns. Beyond the neonatal period, there is a wide age distribution. There is no racial predilection for milia, but milia en plaque and eruptive milia have been observed to be more common in females.

What is the Cause of the Disease?
Etiology
Pathophysiology

Milia are tiny epidermoid cysts and are thus believed to arise from the pilosebaceous unit. Primary milia are thought to originate from the sebaceous collar of vellus hairs, whereas secondary milia are felt to arise mostly from disruption of eccrine sweat ducts. The etiology of milia en plaque, however, remains elusive.

Systemic Implications and Complications

Milia are asymptomatic and benign; no systemic complications have been reported.

Treatment Options

Given their benignity and lack of symptoms, treatment is generally not necessary unless requested by the patient.

Medical treatments supported by single case reports include topical retinoids (topical tretinoin 0.05% or 0.1% cream daily for 1-2 months) and systemic retinoids. The potential side effects of systemic retinoids would preclude one from using these medications as a reasonable therapeutic option. Additionally, minocycline has been reported to effectively treat milia en plaque.

Surgical interventions include simple evacuation by nicking with an #11 blade or hypodermic needle and expressing contents with a comedone extractor or curette. CO2 laser, dermabrasion, mild electrodessication, or electrocautery have also been employed with success.

Optimal Therapeutic Approach for this Disease

Treatment is not necessary. Several medical and surgical interventions have been employed with success and may be selected based on number of lesions and patient preference. Removal with an #11 blade and comedoe extractor for isolated milia is typically very successful.

Patient Management

Patients should be counseled on the benignity of the diagnosis and expected clinical course. Milia in neonates generally resolves within a few weeks, whereas milia in older children and adults tend to be more persistent. Secondary milia also tend to persist. Treatment is generally not necessary unless requested by the patient.

Unusual Clinical Scenarios to Consider in Patient Management

Milia may occur as a feature of many genodermatoses, a careful physical examination is warranted, especially in those patients displaying large numbers of milia. These genodermatoses include, but are not limited to, Bazex syndrome, Rombo syndrome, Brooke-Spiegler syndrome,oro-facial-digital syndrome, atrichia with papular lesions, pachyonychia congenita type II, basal cell nevus syndrome and KID syndrome.

Milia occurring with epidermolysis bullosa, porphyria cutanea tarda, and hereditary porphyrias are best considered as secondary milia.

What is the Evidence?

Berk, DR, Bayliss, SJ. “Milia: a review and classification”. J Am Acad Dermatol. vol. 59. 2008. pp. 1050-63. (Overall excellent review. Discusses classification of milia, great photographs. Discusses genodermatoses that have milia. Briefly describes therapy.)

Bridges, AG, Lucky, AW, Haney, G, Mutasim, DF. “Milia en plaque of the eyelids in childhood: case report and review of the literature”. Pediatr Dermatol. vol. 15. 1998. pp. 282-4. (Discusses a case report of a 10 year old girl with mila en plaque. Treatment consisted of minocycline and manual extraction.)

Connelly, T. “Eruptive milia and rapid response to topical tretinoin”. Arch Dermatol. vol. 144. 2008. pp. 816-7. (Report of an 18-year-old female with eruptive milia on the chest treated successfuly with tretinoin 0.1%. Free of recurrence after 3 years of follow-up.)

Sandhu, K, Gupta, S, Handa, S. “CO2 laser therapy for milia en plaque”. J Dermatolog Treat. vol. 14. 2003. pp. 253-5. (Case report showing good results using CO2 laser for treatment of milia en plaque.)

Thami, GP, Kaur, S, Kanwar, AJ. “Surgical pearl: enucleation of milia with a disposable hypodermic needle”. J Am Acad Dermatol. vol. 47. 2002. pp. 602-3. (Discussion of the one of the most widely used and practical treatment options for solitary milia.)

van Lynden-van Nes, AM, der Kinderen, DJ. “Milia en plaque successfully treated by dermabrasion”. Dermatol Surg. vol. 31. 2005. pp. 1359-62. (Again another case report, this time reporting the use of dermabrasion in the therapy of milia en plaque.)