Dawaa Reference

acute

Photoallergic reaction to sunlight

Treatment options, dosing, cautions and Egyptian brands from the shipped Dawaa Reference card.

Evidence status

Checked against the sources named below

Sources3 sources

DailyMed SetID 8274ca80-e7d3-4f4f-9901-cc5c589b4fef sections 1 and 2.2, https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=8274ca80-e7d3-4f4f-9901-cc5c589b4fef · Levocetirizine dihydrochloride tablets US prescribing information, sections 1 and 2 Dosage and Administration (DailyMed SetID 8274ca80-e7d3-4f4f-9901-cc5c589b4fef) · Sathe NC, Gillespie E. Photosensitivity and Photodermatoses. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan-. Updated 2026 Jan 31. Bookshelf ID: NBK431072; PMID: 28613726.

Verified against1 document
  • DailyMed SetID 8274ca80-e7d3-4f4f-9901-cc5c589b4fef sections 1 and 2.2, https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=8274ca80-e7d3-4f4f-9901-cc5c589b4fef

Verified date2026-08

Presentation reference

Is it this?

Reference only, to read alongside your own examination.

Symptoms — what the patient reports (8)

  • Ask how soon the rash follows light, whether it repeats, whether it swings with the seasons, and how long it lingers once exposure stops [rash]
  • Onset within minutes points to solar urticaria; a delay of hours to days fits photoallergy or polymorphic light eruption [rash · urticaria]
  • A constant rash with little seasonal swing suggests skin lupus or chronic actinic dermatitis instead [rash]
  • Take the whole drug and exposure history: prescriptions, off-the-shelf medicines, herbals, creams, perfumes, plants and workplace chemicals
  • Thiazide water tablets and doxycycline are the drugs most often behind it
  • Joint pains, mouth ulcers, cold blanching fingers or fatigue suggest connective tissue disease behind the rash [fatigue · mouth ulcers · rash]
  • Belly pain, nerve symptoms or dark urine point instead to acute porphyria [abdominal pain]
  • In a child, poor growth, neurological problems or cancers appearing young point to an inherited photosensitivity syndrome [failure to thrive]

Signs — what you find (9)

  • The rash takes the sun-exposed sites: backs of the hands and forearms, the V of the chest, neck and face, while covered skin is spared [rash]
  • Sharp cut-off lines at collars, watch straps, jewellery or the hairline confirm a light-driven pattern
  • Sparing of skin that is exposed every day, such as the face, is a clue to polymorphic light eruption and reflects hardening [rash]
  • Eczema-like plaques favour photoallergy or chronic actinic dermatitis; weals favour solar urticaria [plaques · urticaria]
  • Bumps, plaques, small blisters and itchy nodules are the usual look of the idiopathic photodermatoses [blisters · itching · plaques · vesicles]
  • Ring-shaped plaques that flare in the sun suggest subacute cutaneous lupus [plaques]
  • Blisters, fragile skin and scarring on sun-exposed sites raise porphyria, above all porphyria cutanea tarda [blisters · scarring]
  • Look past the skin: scalp, nails, mucous membranes and for signs of systemic illness
  • Abnormal nailfold capillaries support dermatomyositis; mottled poikiloderma with sun damage suggests long-standing photosensitivity or an inherited syndrome

Tests (10)

  • Work in steps: history and examination first, then targeted bloods, light testing or biopsy only where they are indicated
  • Phototesting is a specialist tool in a few centres only; it pins down the wavelengths at fault and can reproduce the rash
  • Minimal erythema dose testing picks up abnormal sensitivity to UVA or UVB and separates a true photodermatosis from normal skin
  • Repeated UVA or UVB exposures across several days can reproduce chronic actinic dermatitis or polymorphic light eruption, though a false negative is common
  • Photopatch testing is the test when photoallergic contact dermatitis is suspected, run alongside ordinary patch testing to catch allergens that need light to act
  • Guidelines put photopatch testing on eczema-like sun-pattern rashes where the exposure history fits
  • ANA and extractable nuclear antigen panels only when connective tissue disease is suspected, never as routine screening
  • Blistering or painful sun sensitivity needs porphyrin studies on blood, urine and stool
  • Skin biopsy with immunofluorescence helps when the pictures overlap, but the findings are often non-specific and need reading in context
  • Suspected inherited photosensitivity needs specialist-centre work: post-UV cell survival, DNA repair studies or gene sequencing

If not this — what else fits (8)

  • Idiopathic photodermatoses, chiefly polymorphic light eruption and actinic prurigo
  • Skin lupus: think of it in a persistent sun-pattern rash, backed by systemic features, abnormal serology and typical biopsy
  • Dermatomyositis: sun sensitivity together with weak shoulder and hip muscles, or Gottron papules
  • Drug-induced photosensitivity: a recent medicine change plus a sharply sun-limited rash
  • Porphyria: blistering, fragile skin and scarring where the sun reaches
  • Metabolic causes, including the porphyrias and pellagra
  • Inherited photosensitivity syndromes: begin in early life, involve several organ systems, and carry high cancer risk
  • Toxic epidermal necrolysis or Stevens-Johnson syndrome falling in a sun-exposed pattern

SourceStatPearls "Photosensitivity and Photodermatoses" - disease-level clinical article

Presentation findings are traced to the source above.

1

LEVOCETIRIZINE

1st line

Strength5 mg

Formoral.solid

Adult dose and duration

5 mg PO once daily in evening (2.5 mg once daily may suffice). - While symptoms persist; review at 4-6 weeks

Paediatric dose

Age 6-11y: 2.5 mg (1/2 scored tablet) PO once daily in evening; age <6y: use oral solution.

Dose source

DailyMed SetID 8274ca80-e7d3-4f4f-9901-cc5c589b4fef sections 1 and 2.2, https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=8274ca80-e7d3-4f4f-9901-cc5c589b4fef

Why

Standard second-generation antihistamine dose for the itch of an allergic/photoallergic skin reaction; dosing does not change with the trigger for the itch.

Cautions
  • Widespread blistering or systemic symptoms suggesting a severe photosensitivity reaction, or an underlying photosensitising drug that must be stopped.
  • Evening dosing suits itch that is often worse at night.
  • Do not combine with cetirizine - levocetirizine is cetirizine's active component, so together they double the dose.
  • Reduce to 2.5 mg in mild renal impairment.
  • Does not replace photoprotection or stopping a photosensitising drug if one is implicated.
Egyptian brands
Egyptian brandManufacturerIndicative price
ZALKEVOR 5 MG 10 F.C.TABS.EL-OBOUR > REPHARMA5.50 EGP (0.55/unit)
RHIPGIC 5 MG 30 F.C. TABS.P & C LABS19.50 EGP (0.65/unit)
LERGOPAN 5 MG 10 F.C.TABS.PHAROPHARMA7.50 EGP (0.75/unit)
LEVOCITRONE 5 MG 10 F.C.TABS.EGYPHAR21.00 EGP (2.10/unit)
RAMATRIZINE 5 MG 30 F.C.TABS.EGPI > RAMAPHARMA96.00 EGP (3.20/unit)
LEVOHISTAM 5 MG 30 F.C.TABS.EGPI > UTOPIA117.00 EGP (3.90/unit)
ARAXILEVE 5 MG 30 ORO-DISPERSIBLE TABS.JEDCO INT. CO. FOR PHARMACEUTICALS > ARAX PHARM. IND.51.00 EGP
LEVCET 5MG 20 ORODISSOLVABLE TABS.MARCYRL PHARMACEUTICAL INDUSTRIES (MPI)85.00 EGP
MERVOZA 2.5MG/5ML SYRUP 120 ML? strength differs? different route - not oral solidGLOBAL NAPI PHARMACEUTICALS8.00 EGP
MODALLERGE 0.5MG/ML ORAL SOL.? strength differs? different route - not oral solidEGPI > MODERN PHARMA8.00 EGP

Prices are indicative (dataset snapshot 2026-06); verify with the pharmacy.