What it is and what it is for
Phototherapy uses ultraviolet light at selected wavelengths to modulate the skin’s immune system. It does not tan: it treats.
There are two main modalities. Narrowband UVB is today’s standard: effective, with a good safety profile, and requiring no prior medication. PUVA combines a photosensitiser with UVA light, is more potent, and is reserved for selected cases that do not respond.
The indications are real diseases, not cosmetics:
- Psoriasis that is extensive or resistant to topical therapy. The classic indication.
- Vitiligo: still the central tool for repigmentation.
- Atopic dermatitis, moderate to severe.
- Chronic pruritus and other selected inflammatory dermatoses.
Why it is NOT a tanning bed
This must be said with total clarity, because the error is real and it does harm.
A medical cabin emits a specific wavelength (NB-UVB, typically 311 nm), in a dose calculated for your phototype and adjusted session by session, for seconds, with eye and genital protection, and with a lifetime record of cumulative dose — because that dose matters.
A tanning bed emits uncontrolled UVA, in doses designed to darken skin, with no medical judgement. It does not treat psoriasis, it does not repigment vitiligo, and it does raise skin-cancer risk.
If someone suggests “a few tanning sessions” for your psoriasis, you are being badly advised.
What the treatment involves
It is a scheduling commitment, and it is worth knowing before you start:
- Sessions of seconds, but 2 or 3 times a week, sustained. Consistency is the treatment.
- Starting at low doses according to your phototype and increasing gradually, measuring how your skin responds.
- Mandatory eye protection throughout the session, and genital protection in men.
- Cumulative dose is recorded, because long-term risk depends on it. This monitoring is exactly what a medical cabin has and a tanning bed does not.
- The response takes time: measured in weeks of sessions, not two visits.
Who handles it here
Diagnosis and treatment of phototherapy belong to the clinic’s dermatology consultation — the same one with which Dr. Francisco Arellano Ocampo founded the house in 1971. Dr. Arístides Arellano is a plastic surgeon, not a dermatologist: his contribution here is surgical and reconstructive, and the disease itself is managed in the consultation. Book at dermatology consultation.
Dr. Arístides Arellano is a plastic surgeon holding a specialty licence: he practises under a Mexican medical licence (D.G.P. 1125959) and a specialty licence in Plastic & Reconstructive Surgery (0002008), both issued by the Directorate General of Professions (DGP), which reissued his certificate of professional standing in 2025. His career began before Mexico’s present-day specialty-board system existed: he belongs to the founding generation of plastic surgery in Puebla, the second generation of a surgical tradition started in 1971 by Dr. Francisco Arellano Ocampo. Trust is verified, not promised: both licences are public and anyone can look them up in the DGP’s National Registry of Professionals.
Risks and expectations
Every medical treatment —topicals, peels and energy-based devices included— carries risk and requires a prior assessment. In darker skin (Fitzpatrick IV–VI, the most common phototypes in Mexico) a poorly indicated procedure can darken the patch instead of lightening it. Results may vary according to each patient, their phototype and their individual triggers.
Approximate price
A session starts at approximately $500 MXN, depending on the area treated and how many sessions your response calls for. Approximate price — the definitive cost is set at your private consultation with Dr. Arístides Arellano.
Trust is verified, not promised. All 210 scanned documents —degree, licences, diplomas, publications and certificates, from 1977 to 2025— are open in Dr. Arístides Arellano’s credential archive, alongside an explanation of the difference between a specialty licence and a board certification.
Control plan
- IndicationPsoriasis, vitiligo, atopic dermatitis, chronic pruritus.
- ModalityNarrowband UVB (standard) or PUVA (selected cases).
- Frequency2–3 sessions a week. Consistency is the treatment.
- DoseCalculated by phototype, adjusted per session, recorded for life.
- ProtectionEye protection mandatory. Genital protection in men.
- It is NOTA tanning bed. Nothing in common.
Frequently asked questions
Is phototherapy like a tanning bed?
No, and confusing them is dangerous. A medical cabin emits a specific wavelength in a dose calculated for your phototype, for seconds, with eye protection and a record of cumulative dose. A tanning bed emits uncontrolled radiation to darken skin: it does not treat psoriasis, it does not repigment vitiligo, and it does raise skin-cancer risk.
What is it for?
Inflammatory and immune-mediated skin disease: extensive or resistant psoriasis, vitiligo — where it remains the central tool for repigmentation — moderate-to-severe atopic dermatitis, and chronic pruritus. It is not a cosmetic treatment: it modulates the skin’s immune system.
How many sessions do I need?
It is given 2 or 3 times a week, sustained, and the response is measured in weeks of sessions, not two visits. Consistency is literally the treatment: attending irregularly makes it not work. It is worth knowing before you start, because it is a real scheduling commitment.
Is it safe?
It is delivered at doses calculated for your phototype, adjusted session by session, with mandatory eye protection and a lifetime record of cumulative dose, because long-term risk depends on it. That monitoring is precisely what distinguishes a supervised medical cabin from uncontrolled exposure.
What is the difference between UVB and PUVA?
Narrowband UVB is the current standard: effective, with a good safety profile, and requiring no prior medication. PUVA combines a photosensitiser with UVA light, is more potent, and is reserved for selected cases that do not respond to UVB. The choice is made in the dermatology consultation according to the disease, its extent and your phototype.
Every case is different. Discuss yours in a personal consultation.
Book a consultation on WhatsAppEvery figure published on this site is approximate and is not a quote. Any procedure or treatment first requires a private assessment consultation with Dr. Arístides Arellano —$800 MXN, charged separately— and it is at that consultation that the definitive cost of your case is determined.
Educational content; it does not replace a medical consultation. Results may vary from person to person.