Midfacial toddler excoriation syndrome (MiTES)

What is midfacial toddler excoriation syndrome?

Midfacial toddler excoriation syndrome (MiTES) is a rare, autosomal recessive, dysaesthetic disorder starting in infancy that is characterised by severe, self-inflicted facial excoriation with subsequent scarring and dyspigmentation.

Who gets midfacial toddler excoriation syndrome?

Midfacial toddler excoriation syndrome is extremely rare, with the first case being identified in 2017. Onset is typically between 6–12 months of age, and the sex distribution has been reported as roughly equal, though one review noted a male predominance. Parental consanguinity is associated with MiTES.

What causes midfacial toddler excoriation syndrome?

Midfacial toddler excoriation syndrome is a protein-aggregation disorder caused by biallelic mutations in the PR domain-containing protein 12 (PRDM12) gene, specifically an expansion of the polyalanine tract. This tract normally consists of 7 to 15 alanine residues, whereas the presence of 16 to 18 alanines has been linked to MiTES and causes intracellular PRDM12 protein clumping in vitro.

The PRDM12 protein is a transcriptional regulator integral to the development of nociceptive (pain-sensing) neurons.

What are the clinical features of midfacial toddler excoriation syndrome?

Cutaneous features:

• Intense mid-facial itching with persistent scratching and skin rubbing, resulting in excoriations (self-induced erosions and ulcers), crusting, lichenified plaques, significant scarring, and post-inflammatory hypo- or hyperpigmentation
• Symmetrical distribution localised to the face (‘X-shaped’ pattern), particularly the midfacial area eg, nasal bridge, sides of nose, central forehead, infra-orbital areas, and cheeks.
• Alopecia or hair-shaft injuries as a result of chronic rubbing (trichoteiromania) in some patients.

Non-cutaneous features:

• Disturbed sleep
• Nose-pulling and face-slapping behaviour
• Scratching triggered by anxiety or stress as a form of self-soothing
• Otherwise normal growth and development.

Pain sensation is typically preserved in patients with MiTES, but mild pain insensitivity in the face and extremities has been reported in the literature.

Darker skin types are more prone to post-inflammatory pigmentary changes; secondary erythema is more easily appreciable on lighter skin types.

Llchenification and hyperpigmentation over the nose and nasal bridge due to MITES 

What are the complications of midfacial toddler excoriation syndrome?

• Secondary bacterial skin infection of excoriated skin eg, staphylococcal and streptococcal infections
• Permanent scarring and disfigurement
• Psychosocial distress



How is midfacial toddler excoriation syndrome diagnosed?

Midfacial toddler excoriation syndrome is typically diagnosed through a combination of clinical evaluation, exclusion of other conditions, and genetic testing where available.

Suggestive history and exam findings:

• Onset of symptoms by toddler age
• Repetitive scratching or skin rubbing of the face
• Excoriations, crusting, lichenification, scarring, and dyspigmentation of the mid-face in a symmetrical distribution
• Absence of an underlying primary dermatosis
• Parental consanguinity
• Positive family history.

MiTES can be definitively diagnosed by identifying biallelic PRDM12 mutations on genetic testing.

What is the differential diagnosis for midfacial toddler excoriation syndrome?

• Eczema
• Scabies
• Bacterial skin infections
• Other disorders caused by PRDM12 mutations ie, congenital insensitivity to pain (CIP) and hereditary sensory and autonomic neuropathy (HSAN) type VIII.
• Non-accidental injury
• Dermatitis artefacta
• Compulsive skin picking
• Trigeminal trophic syndrome
• Hereditary neuropathies
• Localised epidermolysis bullosa

What is the treatment for midfacial toddler excoriation syndrome?

There is no cure for midfacial toddler excoriation syndrome. Treatment primarily focuses on managing the scratching behaviour, promoting skin healing, and addressing any underlying emotional or behavioural factors. These include:

• Behavioural therapies (eg, habit reversal training, cognitive-behavioural therapy) to modify the child’s response to itching or distress, thereby breaking the compulsive scratching cycle.
• Regular application of emollients and moisturisers to reduce skin dryness or irritation, thereby minimising the urge to scratch.
• Basic wound care to prevent secondary skin infections and encourage healing of excoriated skin eg, cleansing with mild soap and water, applying a non-stick bandage or dressing
• Soft mittens or scratch sleeves to prevent the child from scratching during sleep or times of heightened stress.
• A mild topical corticosteroid (eg, hydrocortisone) for significant inflammation.
• Topical antiseptics or oral antibiotics to treat secondary bacterial infections.
• Identifying and eliminating potential triggers (eg, environmental stressors, allergens, irritants) that might cause the child to scratch.

How do you prevent midfacial toddler excoriation syndrome?

There is no known way to prevent midfacial toddler excoriation syndrome. Reproductive genetic counselling and pre-implantation genetic testing can be offered to known carriers of a pathogenic variant or affected individuals.

What is the outcome for midfacial toddler excoriation syndrome?

Midfacial toddler excoriation syndrome is self-limited in most cases, with the itching and excoriation behaviours subsiding during the first decade of life. While excoriated skin typically heals with skin care, scarring and pigmentary changes can persist.