Fulminant rosacea: what is this rare and severe form of rosacea?

The etiology of fulminant rosacea is still under study. However, infectious and inflammatory components are strongly suspected. The potentially responsible infectious entities include bacterial folliculitis, cutaneous nocardiosis, deep fungal infection, or atypical mycobacterial infection. Various studies conducted on fulminant rosacea confirm a bacterial infection in 31% of affected patients, due to a variety of microorganisms rather than a single pathogen.

Furthermore, it has been observed that fulminant rosacea often accompanies a dermal inflammatory infiltrate both superficial and deep, composed of neutrophils, lymphocytes and eosinophils, with a predilection for perifollicular and sebaceous structures. These various inflammatory agents play a crucial role in the immune response and are mobilised when the body needs to defend itself.

Finally, it appears that there is a link between fulminant rosacea and hormonal fluctuations. Indeed, a few cases have been reported at the beginning of pregnancy, suggesting the triggering role of hormonal factors in predisposed women. In the few reported cases, skin improvement was rapid within the month following childbirth. A change in oral contraception was also frequently observed in patients, shortly before the onset of fulminant rosacea, which reinforces the hypothesis that hormones play a role.

The treatment of fulminant rosacea primarily relies on the use ofisotretinoin, at a dosage of 0.5 mg/kg per day. This derivative of vitamin A belongs to the retinoid family and is particularly used in cases of persistent inflammatory acne. From a mechanistic perspective, isotretinoin blocks the activity of the sebaceous glands, thereby inhibiting sebum production. In doing so, it halts the proliferation of microorganisms that feed on it.

Beyond isotretinoin, tetracyclines, a group of bacteriostatic antibiotics that also possess anti-inflammatory properties, have sometimes been used successfully. Scientists also report cases of the use of oral erythromycin, whether combined with oral corticosteroids or not, in pregnant women suffering from fulminant rosacea as isotretinoin and tetracyclines are contraindicated during pregnancy. In several studies, oral erythromycin proved to be minimally effective in controlling symptoms and isotretinoin was introduced post-delivery, which led to an improvement in symptoms.

When considering the available scientific data as a whole, it is observed that oral corticosteroids and isotretinoin are treatments of choice in cases of fulminant rosacea, unless other factors, such as pregnancy, make their use impossible. In these instances, oral antibiotics are considered, however, patients are warned that this treatment alone may not be sufficient.

Please note : while papulo-pustular lesions generally disappear within a few weeks after the start of a treatment, erythema often persists for several months.