Bioderma Congress Reports JDP 2025

Subcutaneous neurofibromas and differential diagnosis 

Speaker: Sébastien Barbarot (France) 

There are six questions to ask when faced with café au lait spots (CALSs) 

1. CALSs or not?  

2. CALSs typical of NF1? 

3. Age?  

4. Number? 

5. Family history?  

6. Other signs? 

Algorithm for managing CALSs in children:  

Patients with three CALSs represent 20% of the population.  

Differential diagnoses for CALSs:  

• Mastocytosis  

• Clear congenital naevi or early naevus spilus. These are often single lesions. Clinical follow-up is useful in making the diagnosis. Confocal microscopy is an excellent tool for making the distinction   

• Becker’s hamartoma 

• Pigmentary mosaicism (phyloid, blaschkolinear) 

A CALS suggestive of NF1 is a rounded oval macule with a clear border, sparing the cephalic extremity. Lesions are generally present at birth and lentigines appear around the age of two to three years. Neurofibromas (NFs) appear later and are highly polymorphic. They are either superficial, maculopapular with skin atrophy, or subcutaneous, forming small, firm nodules along nerve pathways. Their presence is a factor for poor prognosis and the presence of internal neurofibromas.  

Large CALSs can become progressively hairy and may be associated with the presence of plexiform NFs. Plexiform NFs can also be atrophic, but this is a rarer clinical presentation.  

There is also a segmental presentation of NF1, which corresponds to type 1 (due to a postzygotic mutation) or type 2 mosaicism, based on the second-hit hypothesis.  

There may be other associated clinical signs: 

• Naevus anaemicus has a prevalence of 50% but is also observed in other RASopathies. 

• Juvenile xanthogranulomas are present in ⅓ of cases, appear before four years of age and are transient. 

Other conditions with CALSs:  

1. Legius syndrome 

• SPRED1 mutation
• CALSs and isolated lentigines
• 50% have at least two NF1 criteria
• Learning disability in 20% of cases
• Macrocephaly
• Lipoma
• No Lisch nodules, no NFs, no optic pathway tumours 

Report written by Déborah Salik (dermatologist, Belgium) 

Chairs: Thomas Hubiche (France), Sébastien Barbarot (France), Hamida Turki (Tunisia) 

Speakers: Isabelle Luchsinger (Switzerland), Malek Cherif (Tunisia), Constance Deblock (France), Juliette Mazereeuw-Hautier (France), Rajaa Bousmara (Morocco) 

X-linked hypohidrotic ectodermal dysplasia: specific phenotype in female transmitters 

Speaker: Isabelle Luchsinger (Switzerland) 

X-linked hypohidrotic ectodermal dysplasia is the most common form of ectodermal dysplasia. The phenotype of female carriers is poorly characterised. 

          Objective: Describe the symptoms in women who transmit the disorder. 

          Method: Prospective study including women with a variant in the EDA gene. 

          Results: 36 women with: 

Dental: 

• Persistence of baby teeth (44%) 

• An anomaly in shape: conoid teeth (42%) 

• Hypodontia 

Dermatological: 

• Eyebrows: hypotrichosis in 78% of cases and fine hairs in 83% 

• Eyelashes: partial hypotrichosis in 75% of cases 

• Scalp: hypotrichosis and fine hair associated with slow hair growth  

• Body hair: total alopecia and blaschkolinear hypotrichosis in 75% of cases. This reflects mosaicism  

• 80% of women reported perspiration problems and regular fainting 

• Dry skin and increased atopic diathesis (53%) 

• Dry mucous membranes: xerostomia, xerophthalmia, hoarse voice, genital dryness 

Breast abnormalities: 

• Significant breast asymmetry (53%) 

• Exceptionally flat nipples in 2/3 of women and absence of Montgomery glands, associated with breastfeeding difficulties  

Conclusion: It is important to be able to identify female transmitters based on clinical criteria. These women deserve appropriate multidisciplinary support. 

Palmoplantar keratoderma in autosomal recessive congenital ichthyosis: clinical and genetic features 

Speaker: Malek Cherif (Tunisia) 

ARCI is a heterogeneous group of non-syndromic ichthyosis.  

Aim of the study: to describe the different aspects of palmoplantar keratoderma (PPK) in ARCI and to establish a phenotype-genotype correlation. 

Method: A 20-year retrospective study of patients with ARCI. Evaluation of the features of PPK in these patients according to their genotype.  

Results: 41 patients  

• PPK in 95.1% of cases 

• NIPAL4 gene: Yellowish discolouration in 60% cases and diffuse involvement in 48% with plantar depression in 52% 

• TGM1 mutation: Constant PPK but of variable intensity and constant palmar hyperlinearity. Brachydactyly in 87.5% of cases 

• SULT2B1: Constant PPK; mild on the hands, moderate on the feet, sparing the plantar arches  

• CYP4F22: Mild PPK with palmoplantar hyperlinearity  

• CERSE: Aged appearance of the backs of the hands with palmoplantar hyperlinearity 

• ABCA12: No PPK and no brachydactyly  

Effectiveness of a targeted high-throughput sequencing panel for the molecular characterisation of ichthyosis 

Speaker: Constance Deblock (France) 

Inclusion criteria: Molecular analysis and clinical diagnosis 

Panel of 38 genes associated with ichthyosis 

Patients classified according to conclusive gene: class IV or V 

Inconclusive: No pathogenic variant or a single heterozygous variant 

Results: 90% of patients obtained a conclusive result 

Inconclusive results: 11% (n=33) had whole-genome sequencing: Five had a conclusive result 

Conclusion: The panel was of interest because it was very effective, which was a quick step, but regular updating is essential. Whole-genome sequencing is useful for finding non-coding or structural variants. 

Ichthyosis linked to variants in the ELOVL1 gene: a rare and poorly understood syndromic form of ichthyosis 

Speaker: Juliette Mazereeuw-Hautier (France) 

Congenital ichthyosis is classified into three groups: 

• Palmoplantar keratoderma (PPK)  

• Non-syndromic ichthyosis  

• Syndromic ichthyosis caused by various genes including ELOV1 

          ELOV1 is essential for the synthesis of long-chain fatty acids in the skin 

          ELOV1: AD form and AR form 

Study of the c.494C>T variant (p.Ser165Phe) 

Phenotype 

• Cutaneous: erythematous and scaly plaques 

• Neurological: delayed acquisition of walking or lack of acquisition associated with pyramidal signs  

• Ophthalmological: Appearance of strabismus and nystagmus 

Discussion: This ELOV1 variant is associated with a characteristic triad of dermatological, ophthalmological and neurological signs. 

Neurological signs are at the forefront of the disease and are a major cause of its severity. 

No correlation between cutaneous and neurological severity. 

Pathophysiological hypothesis: dominant negative effect 

Enables targeted therapeutic approaches to be considered by inhibiting the mutant mRNA using an antisense oligonucleotide approach. 

Efficacy and safety of topical gentamicin 0.1% in inherited epidermolysis bullosa 

Speaker: Rajaa Bousmara (Morocco) 

Inherited epidermolysis bullosa (IEB) is a genodermatosis that causes skin and mucous membrane fragility.  

No curative treatment at present, but an emerging concept: stop-codon readthrough to enable synthesis of a complete protein.  

Study: Evaluation of the effect of gentamicin 0.1% applied twice a day for 21 days.  

Four patients had DEB and JEB. 

The results showed very good, fairly rapid healing after one month, but this was marked by cases of recurrence over the longer term (three months on average). 

Gentamicin B1 has strong nonsense mutation suppression activity and promotes collagen VII synthesis.  

Gentamicin is a promising therapeutic option for IEB linked to nonsense mutations. 

• Well tolerated 

• Easy to apply  

• Low cost  

It is an alternative to gene and cell therapies, which are often inaccessible. 

Intravenous gentamicin may provide improvement for up to six months and is well tolerated. Studies are under way to determine the appropriate doses for children in order to limit the side effects.  

Report written by Nicolas Kluger (dermatologist, Finland) based on: 

• De La Rochefoucauld et al. Facteurs prédictifs de réponse à l’anifrolumab dans le lupus cutané : une cohorte prospective de 57 patients. CO95 

• Moschkowitz et al. Évaluation de la possibilité d'espacement des perfusions d'anifrolumab chez les patients lupiques répondeurs. CO94 

• Le Bellour et al. Efficacité de l'anifrolumab dans les panniculites lupiques : étude rétrospective de 11 patients. CO96 

• Mollet et al. Herpès vulvaire chronique résistant à l’aciclovir et induit par l’anifrolumab. P186 

• Russo et al. Psoriasis paradoxal induit par l'anifrolumab chez une patiente atteinte de lupus cutané sévère : caractérisation par la médecine de précision. P236 

Anifrolumab is a monoclonal antibody used to treat moderate to severe systemic lupus erythematosus by blocking the type I interferon receptor, an overactive pathway in lupus patients. It has had marketing authorisation since 2022 for systemic lupus with active skin involvement despite standard treatment.  

Anifrolumab has rapid and comparable efficacy across the different subtypes of cutaneous lupus: discoid, subacute, acute and chilblain lupus. Efficacy appears to be better in patients with a moderate (rather than severe) CLASI activity score at treatment initiation. However, there are few predictive factors for response, apart from the level of interferon activity and the interferon signature (CO95).  

It is administered intravenously (300 mg every four weeks) on an outpatient basis. This raises the question of spacing out infusions in patients in remission. A prospective study (still in progress) aimed to assess the relapse rate during dose spacing. Relapse was noted in a third of cases in a series of 78 patients with a median duration of 11.5 months after the start of spacing (22% at 12 months, with spacing at eight weeks) (CO94). 

Le Bellour et al. reported significant efficacy with anifrolumab in a small series of patients with lupus panniculitis (LP). LP is a rare form of cutaneous lupus; it is often resistant to conventional therapies (hydroxychloroquine, oral corticosteroids, methotrexate, etc.). It may be isolated or associated with systemic involvement or other forms such as DL or chilblain lupus. The efficacy of the treatment was noticeable at six months, although some skin sequelae inherent in panniculitis were observed.  

These results are encouraging in this form of cutaneous lupus, but the role of anifrolumab remains to be determined. 

DM can be paraneoplastic and associated with other paraneoplastic syndromes, as in a case of acquired hypertrichosis lanuginosa with a poor prognosis (P345). 

On melanin-rich skin, juvenile dermatomyositis (JDM) presents with classic symptoms such as erythema or oedema of the eyelids as well as Gottron papules on the backs of the hands. Emphasis should be placed on the hypopigmented poikilodermic appearance of the trunk, which is particularly noticeable on dark skin and can be disconcerting at first sight. Necrotic lesions appear achromic (P126). 

Lastly, periocular/palpebral involvement in DM should not be confused with the fixed, painless, oedema-free periorbital erythema described by Cordel et al. in Still’s disease (P343). 
 

Therapeutically,  

Hydroxychloroquine (HCQ) is considered to be effective against the skin damage caused by DM/JDM, either alone or in combination. However, there is little data in the literature and its efficacy varies widely from > 10% to 75%. A multicentre retrospective study compared 57 patients who had received HCQ and 45 who had not. In total, 46% of patients treated with HCQ achieved a complete skin response, compared with 75% in the group without HCQ. In multivariate analysis, only HCQ was significantly associated with a lower rate of complete response. Overall, HCQ appears to be associated with a lower rate of complete skin response. Prospective studies or studies involving larger numbers of patients are needed to confirm these results. 

Anifrolumab could be a promising option in severe juvenile forms resistant to conventional therapies (P105). 

Based on this review, an expert consensus was established between the GFELC and GREAT members using the DELPHI method: 

• Contraindication of dupilumab if there is a history of cTCL in a patient with AD 

• Investigate/rule out cTCL before starting dupilumab when there is late-onset AD (> 40 years), absence of atopy and AD with an atypical clinical presentation. Carry out a skin biopsy to test for T-cell clonality. Erythrodermic AD or AD > 50% of body surface area should also be investigated by a specialist 

• If there is atypical worsening or if new lesions appear during treatment with dupilumab, rule out cTCL  

• If cTCL is confirmed, stop dupilumab, report the case to pharmacovigilance and treat the cTCL according to the aggressiveness of the clinical form 

• If cTCL is not confirmed, close monitoring is recommended (repeat biopsies and blood tests if lesions persist), with a transition to methotrexate or phototherapy. Avoid cyclosporine, JAK inhibitors and other inhibitors of the Th2 pathway 

All in all, this review of the literature points to a link with patients with late-onset adult AD, with no history of atopy, and with the aggravation of pre-existing lesions. When the bioavailability of IL-13 is increased on dupilumab, this cytokine could bind to the IL13Ralpha2 receptor, which is not blocked by dupilumab, but is over-expressed in certain types of cancer. This suggests that reported cases more likely represent unmasked or previously undiagnosed cTCL. The other anti-Th2 biotherapies used in AD (tralokinumab, lebrikizumab) have a different mechanism to dupilumab, but there is currently insufficient hindsight to rule out a risk.  

Report written by Nicolas Kluger (dermatologist, Finland) based on: 

• Benzaquen M and Rongioletti F. Nouvelles entités et dermatoses inhabituelles ou trompeuses à connaitre en pratique. FMC079 

• Kluger N. Tout ce que vous avez toujours voulu savoir sur la dermatologie et la cosmétologie de la peau asiatique. FMC029 

• El Lakkis et al. Une dermatose en or / une dermatose oubliée. Top 12 des Juniors  

• Bois F et al. Quand la radiothérapie fait parler la peau. Laroche Posay Dermacademy symposium 

Focal epithelial hyperplasia (FEH or Heck’s disease) is a benign condition of the oral mucosa caused by HPV infection, mainly types 13 and 32. It mainly affects children and teenagers, but can also occur in adults. It is rare. In Europe, it is common in cases of HIV infection or organ transplantation. It manifests as multiple small, soft, painless, non-ulcerated pinkish or whitish lesions, mainly on the lips, cheeks and tongue. The disease is non-cancerous and often self-limiting, disappearing spontaneously within a few months or years. Diagnosis is usually clinical and is sometimes confirmed by biopsy with HPV PCR for typing. Treatment is not always necessary, and observation may be sufficient, but curettage, cryotherapy, imiquimod or CO2 laser ablation may be proposed for functional or aesthetic reasons. 

Reports written by Ibrahima Traoré (dermatologist, Guinea) 

Chair: Fatimata Ly (Senegal) 

Speakers: Fatimata Ly (Senegal), Mariem Kebe Dia (Mauritania), Mame Thierno Dieng (Senegal) 

Voluntary cosmetic depigmentation (VCD): Background and motivations 

Speaker: Mame Thierno Dieng (Senegal) 

Mame Thierno Dieng introduced the issue of VCD by briefly tracing its historical background and socio-cultural roots. He explained how this practice, initially limited to certain social groups, has gradually spread in many countries in sub-Saharan Africa. 

Key points 

• VCD is based on an ancient phenomenon that has been influenced over time by aesthetic standards that value fair skin. 

• The most common motivations include: 

• The search for a beauty ideal associated with lighter skin, perceived as a sign of modernity or social success. 

• The influence of social pressure and social media, reinforcing certain aesthetic standards. 

• The impact of cosmetics marketing, which is often aggressive and poorly regulated. 

• Psychological motivations, in particular self-esteem and the desire to belong. 

• The most commonly used depigmenting agents: hydroquinone, potent corticosteroids (clobetasol propionate), mercury derivatives, injectable or oral glutathione, kojic acid. 

Prof Dieng stressed the need to understand the underlying motivations in order to better guide prevention and management strategies, which should include an educational and socio-cultural component. 

Infectious complications of voluntary cosmetic depigmentation 

Speaker: Mariem Kébé Dia (Mauritania) 

Mariam Kébé Dia discussed the infectious complications associated with VCD, focusing on skin immunosuppression induced by the prolonged use of corticosteroids and other depigmenting agents. 

Key points 

• Dermatophytoses are the most frequent infectious complication, promoted by: 

• skin barrier impairment, 

• reduced local immune defences, 

• moisture and maceration associated with the products applied. 

• Other possible infections (mentioned more briefly): 

• bacterial: impetigo, folliculitis, erysipelas; 

• viral: molluscum contagiosum, warts; 

• parasitic: secondarily infected scabies. 

• Diagnosis is based on a careful clinical examination and, if possible, a mycological sample. 

 
Prof Kébé Dia pointed out that management should combine anti-infectious treatment, discontinuation of dangerous depigmenting products and education about the risks of these practices. 

Non-infectious complications of voluntary cosmetic depigmentation 

Speaker: Fatimata Ly (Senegal) 

Fatimata Ly presented the non-infectious complications, which are often severe and largely underestimated, with a particular focus on the risk of cancer. 

Key points 

• Squamous cell carcinoma: a major complication linked to skin thinning, photosensitisation and prolonged exposure to depigmenting agents. 

• Other non-infectious complications observed: 

• Steroid dermatitis: atypical stretch marks, skin atrophy, telangiectasias. 

• Pigment disorders: dyschromia, hypopigmented patches, exogenous ochronosis. 

• Renal or neurological complications due to mercury derivatives. 

• Systemic effects of corticosteroids in the event of massive use. 

• The products concerned are the same agents frequently used in VCD: hydroquinone, mercury, fluorinated corticosteroids, glutathione and kojic acid. 

Prof Ly stressed the urgent need to step up the regulation of depigmenting products, improve community awareness and develop appropriate management strategies, including rigorous dermatological monitoring.