Акценти от 4-ти ден

Dr. Lise Boussemart

Dermatologist, Rennes, France

Fundamentals of Dermoscopy

Dr. Claudia Hernandez, Dermatologist, United States
Dr. Caterina Longo, Dermatologist, United States
Dr. Pedram Gerami, Dermatologist, United States
Dr. Mary C. Martini, Dermatologist, United States
Dr. Jason Bok Lee, Dermatologist, United States
Dr. Jennifer A. Stein, Dermatologist, United States

 

Dear all,

For the 4th day of the AAD Meeting, I signed up for a training session on dermoscopy. It was very accessible, even for beginners.

The first two speakers, Dr C. Hernandez and Dr C. Longo, reviewed the dermoscopic criteria used to distinguish between melanocytic and non-melanocytic lesions, whose terminology was recently standardised by the International Dermoscopy Society (Kittler et al., JAAD 2016).

Each criterion was illustrated with the corresponding anatomopathological image, which shed light on the patterns observed in dermoscopy (Yelamos et al., JAAD 2019).

For example, the pseudopods observed at the periphery of a melanoma correspond to junctional confluent nests of malignant melanocytes.

Angulated lines in a zigzag pattern correspond to the confluence of atypical melanocytes along the junction, with the presence of dermal melanophages in extrafacial lentigo maligna melanomas in particular.

A mesh network, gradually disappearing at the periphery of junctional naevi, corresponds to the melanocytes surrounding the dermal papillae, viewed from above.

Dermatofibromas are the only non-melanocytic lesions with a similar but very fine mesh network. Dermatofibromas nonetheless often have a central whitish area that appears to be a scar.

An inverse network (white lines on a brown background, instead of brown lines on a white background) is observed in Spitzoid melanomas and Spitz naevi. According to Dr P. Gerami, Spitz naevi mainly occur without photoageing, in young subjects, with a symmetrical pattern and the presence of perpendicular white lines.

Dr M. Martini reviewed the evocative signs of melanoma, such as a white-blue veil (significantly associated with BRAF mutational status according to the recent publication by Armengot-Carbo et al., JAAD 2018), radial streaming, open meshes, asymmetrical distribution of blood cells, and blue-grey dots on hypopigmented areas, synonymous with regression.

But she reiterated that the “ugly duckling” sign remains essential in her practice, even when dermoscopy is reassuring. Polarised light can be used to view an additional sign in favour of melanoma: shiny spots. If a lesion is too dark to identify structures, some of the central dark spots can be removed with tape.

Seborrhoeic keratoses are always identifiable via their milia-like clods (white, visible mainly with non-polarised dermoscopy) and their pseudo-comedones (yellowish but sometimes artificially coloured following hair colouring). These are the same lesions at different stages: milia clods start below the stratum corneum and are then evacuated through it in the form of more superficial pseudo-comedones. Early-stage seborrhoeic keratoses start with a “fingerprint” pattern before progressing to a cerebriform pattern.

Dr Jason Lee insisted on the benefits of dermoscopy for avoiding biopsies with basal cell carcinomas: arboriform telangiectasias, ulceration, and with polarised light only: presence of white structures. Bluish ovoid nests indicate dermal invasion whereas spoke-wheel areas, maple-leaf areas or brown concentric circles are signs of superficial involvement.

Arboriform telangiectasias can also be seen in trichoblastomas, trichoblastic carcinomas, cutaneous B-cell lymphomas and scars.

Dr J. Stein spoke of melanonychia, relying on the recommendations of Jin et al., JAAD 2016. The criteria in favour of malignancy are asymmetry (2 pts), several colours (1 pt), an uneven border (1 pt), a width > 3mm (1 pt) or 6mm (2 pts) and Hutchinson's sign (2 pts). A score > 3 should motivate a biopsy (Ohn et al., JAMA Dermatol 2018). This score has 89% sensitivity and 62% specificity. If ethnic melanonychia is suspected, the presence of some associated lentigines on the palms is a strong argument in favour of the ethnic nature. Dr Stein also recommended the threshold >7 mm in maximum diameter for the excision of any acral naevus whose pigmentation is not typically located in furrows (Koga et al., Arch Dermatol 2011). Note, however, a pattern specific to congenital acral naevi, which is good to know: the “peas-in-a-pod” pattern, i.e. a combination of the crista dotted and parallel furrow patterns (Minagawa et al., Arch Dermatol 2011).

In cases of doubt, the speakers agree that monitoring after three months is acceptable for flat lesions but that direct excision is necessary for any palpable suspicious lesion.

Dr. Nicole Jouan

Dermatologist, Brest, France

Vitiligo

Prof. Thierry Passeron, Dermatologist, France

In the event of rapid progression observed by the patient, an uneven hypopigmented border on Wood's lamp examination or confetti-like depigmentation, we block progression with mini-pulses of oral corticosteroids, 5 mg twice a week on two consecutive days for three to six months and/or narrow-band UVB therapy. Another strategy: methotrexate 10mg/week or minocycline 100mg/day (low level of evidence). For repigmentation: strong local corticosteroids five days/week or three weeks/four or tacrolimus 0.1% or pimecrolimus 1% twice daily combined with narrow-band UVB therapy. Low level of evidence for topical vitamin D derivatives and antioxidants. Maintenance treatment: topical tacrolimus 0.1% twice a week.

Emerging treatments: afamelanotide: can be useful for dark skin, convincing observations and trials in progress with JAK inhibitors, topical JAK inhibitors effective in combination with UVB therapy, and more on the face than on the hands-feet. Stay tuned... Apremilast: solid theoretical bases in favour of its potential efficacy, trial in progress. Topical prostaglandin E2? Topical Wnt agonists?

Vaccinations in immunocompromised subjects

According to the European League Against Rheumatism, severely immunocompromised patients are those undergoing biotherapy or taking more than 20 mg/day of prednisone or equivalent or >0.4 mg/kg/week of methotrexate or >3 mg/kg/day of azathioprine.

• MMR: think of it during this period when measles is making a comeback in France, especially if the patient was born after 1980. Blood test if in doubt, or revaccination four to six weeks before starting treatment (live vaccines are contraindicated during biotherapies).
• HPV vaccination before the age of 26.
• And of course flu every year, pneumococcus and vaccination schedule up to date.
• Hepatitis B depending on the context.

Remember to discuss vaccination with family members who can potentially contaminate the patient!

“Alternative”, “gentle” medicines, adjuvant therapies

These are increasingly popular among our patients, looking for “natural” and “non-chemical” treatments. Very few studies with an adequate level of evidence (which does not mean everything should be discarded!!!)

Hygiene

The general public seems aware that the microbiome can potentially be harmed by antiseptics and detergents. The FDA has withdrawn triclosan. So why not hygiene products containing “good bacteria”, or pro- and pre- and post-biotics to restore the commensal flora? The company MotherDirt markets “biome-friendly” soaps and sprays containing “ammonia-oxidising bacteria”. It's a bit complicated for the FDA to approve products that can be described as contaminated, to say the least! The transplantation of bacteria in eczema is still a long way away, but this is undeniably part of the same approach.

Acne

Tea tree oil: better tolerated but not quite as effective as benzoyl peroxide (but more allergenic)

2% cream green tea extracts: effective for 58% of acne patients in an open-label study

Resveratrol: grape polyphenol, in cream form, 54% decrease in lesions in a study where the patients were their own controls (one half of the face)

Aloe vera: improves tolerance with irritant treatments (a good-quality study with topical tretinoin)

Oral zinc: well known, useful for pregnant women

Oral nicotinamide (vitamin PP) is rather effective at 700 to 1000 mg/day =Oral vitamin A: not recommended due to its high-dose toxicity

Vitamin B5: no demonstrated effects

Saw palmetto extracts?

Probiotics??? Difficult to recommend them in the absence of studies and given the multiple compositions on the market...

Diet: watch out for “large quantities” of skimmed milk, as well as food supplements containing whey proteins (can be replaced with food supplements containing plant proteins)

Wounds

In vitro studies have demonstrated the anti-inflammatory and healing properties of turmeric. The speaker recommends a dose of at least 4 grams per day divided in two and combined with black pepper. Enjoy!

Hidradenitis suppurativa

The link to obesity is known, with established nutritional errors related to the severity of the disease: relevance of the Mediterranean diet deemed to be anti-inflammatory?

Relevance of antimicrobial clothing containing silver fibre (to combat odours), as well as soft and absorbent bamboo fibre bra “liners”

A major trend: bath products containing cannabidiol

If prescribing high-dose zinc, consider the copper depletion it may cause

Eczema

Always use diluted bleach baths during flare-ups

To restore the skin barrier:

the emollient properties of sunflower oil, better tolerated than olive oil, and especially coconut oil, with demonstrated anti-staphylococcus properties

Keep in mind the benefits of massage (20 mins per day)