Your concern
Dermatitis
Atopic, seborrhoeic and contact dermatitis: identifying the type and managing it over time.
"Dermatitis" does not describe a single disease: it covers different conditions, with different mechanisms, that can look very much alike. Itching, redness and scaling appear in almost all of them, and a single symptom is rarely enough to tell them apart. What is needed first is therefore not a cream, but an understanding of which dermatitis is involved: the right therapy for one form can be ineffective, or counterproductive, for another.
Contact dermatitis has two distinct mechanisms. In the irritant form, a substance or a repeated exposure damages the skin barrier faster than the skin can repair it: no true allergy is required. In the allergic form the immune system recognises a particular substance as an allergen, and the reaction can appear even after years of tolerated use. Diagnosis is guided by the distribution of the lesions, the products used, occupation, the timing of onset and, where indicated, allergy testing.
Atopic dermatitis has a different origin. The outermost layer of the skin normally limits water loss and the entry of irritants and allergens; in atopic dermatitis this function may be impaired. A more permeable barrier makes interaction with external stimuli easier, and certain inflammatory signals in turn interfere with the proteins and lipids required for normal skin function. Reducing it to "very dry skin" underestimates its biology: dryness is a manifestation, not the cause.
Seborrhoeic dermatitis affects specific areas — scalp, eyebrows, sides of the nose, ears and other regions rich in sebaceous glands — and the distribution is itself diagnostic information. Malassezia yeasts are a normal part of the skin microbiota: what matters is the relationship between microorganisms, sebum, barrier and the host's inflammatory response. It is not a matter of poor hygiene, and washing aggressively does not correct the mechanism: if anything it increases irritation.
Many forms of dermatitis are chronic and relapsing: they go through phases of improvement and phases of flare-up. Management therefore distinguishes two different moments — the active phase and long-term maintenance — and the return of symptoms does not automatically mean the diagnosis was wrong or that the previous course was of no use.
The itch that feeds itself
Inflammatory mediators and cutaneous nerve endings both take part in the perception of itch. Scratching brings brief relief, but repeated rubbing damages an already vulnerable barrier: micro-lesions and inflammation can reignite the itch, and in chronic cases the skin may thicken precisely because of repeated scratching. Breaking the itch-scratch cycle is not a secondary detail: it is part of management, just as much as treating the acute phase.
How it shows
- Itching, often the most persistent symptom
- Redness and scaling, with plaques of variable outline
- Swelling and a burning sensation during acute phases
- Dry, cracked, tight-feeling skin
- Scratch lesions and, in chronic forms, thickened skin
- Characteristic location: flexures in atopic, sebaceous areas in seborrhoeic, contact areas in contact forms
How we proceed
- 1Dermatological visit: clinical history, skin examination and distribution of lesions
- 2Identification of the type of dermatitis, which guides everything that follows
- 3Where a contact form is suspected, reconstruction of daily and occupational exposures
- 4Patch testing when clinical suspicion justifies it (available at the Siena practice)
- 5Treatment of the active phase and then a maintenance plan with scheduled follow-up
Available treatments
- Dermatology visit
- Identification of the type of dermatitis
- Topical and systemic therapy
- Patch testing (Siena practice)
- Maintenance plan and follow-up
Book a visit
Our specialists will evaluate your case and define the most suitable treatment plan.
Book in FlorenceBook in SienaSiena · Firenze
Where to find us
Frequently asked questions
Why does dermatitis come back even after it has improved?+
Many forms of dermatitis are chronic and relapsing: they can go through phases of improvement and phases of flare-up. A treatment can effectively control an active phase without removing the predisposition that makes that skin more reactive. Management therefore distinguishes two different moments, the acute phase and long-term maintenance. The return of symptoms does not automatically mean the diagnosis was wrong or that the previous course was useless.
Is it because of the way I wash?+
No. Scaling, redness and a greasy or irritated feeling often lead people to wash more, and more aggressively, but cleansing acts on the surface while the mechanism of dermatitis involves the skin barrier, the inflammatory response and, in some forms, interaction with microorganisms normally present on the skin. Washing too often or too vigorously can worsen irritation rather than reduce it.
Can I have become allergic to a product I have used for years?+
Yes, and it is one of the least intuitive aspects of allergic contact dermatitis. For a reaction to appear, the immune system must first become sensitised to a particular substance: a phase that can occur without obvious symptoms, and even after a long period of tolerated use. The fact that a cream, a fragrance, a dye or a material has been used for years without problems therefore does not allow it to be ruled out.
Does atopic dermatitis go away with age?+
The course is variable and cannot be predicted from a single moment in time. In some people the manifestations decrease over the years, in others the skin remains more reactive into adulthood, with periods of wellbeing alternating with flare-ups. The areas involved can also change over a lifetime. Assessment therefore considers the course over time, not only the current phase.
Should I stop using all my products?+
It is the most instinctive reaction when a contact reaction is suspected, but it is rarely the most useful path. Removing everything at once makes it impossible to understand which substance was involved and leaves the skin without adequate cleansing and hydration. The more rational approach is to simplify the routine and rebuild it methodically, together with the physician: when clinical suspicion justifies it, patch tests help identify specific sensitisations instead of proceeding by random elimination.
Related reading
Have a question? Let's talk.
Book a first visit: the physician will evaluate your situation and guide you to the most suitable treatment.
Book a dermatology visit