Phytophotodermatitis: still a poorly recognised diagnosis

Description

A 30-year-old man, forestry worker, with no medical history, presented acutely with pruritic erythematous streaks and bullae (figure 1) in linear configuration on his arms. On the previous day he had pruned branches from a fig tree and carried them with his forearms wearing a sleeveless shirt. Symptoms gradually resolved over 4 weeks of topical treatment with clobetasol propionate 0.05% cream (figure 2).

Figure 1.

Bullae and irregular pigmented lesions on both arms.

Figure 2.

Recovered skin 2 months later.

Furocoumarins are botanical phytoalexins found in a wide variety of plants, including the fig tree (Ficus carita; Moraceae family), which may induce a skin photosensitivity reaction following ultraviolet A radiation exposure.^{1 2} The acute lesions often present with irregular erythematous streaks or bullae with sharp demarcation between lesional and uninvolved skin.^1–3 As the acute eruption clears, it is replaced by hyperpigmented macules that may take months to years to resolve.^{1 2}

Although phytophotodermatitis is not infrequent, it occurs most commonly after exposure to limes or other citrus fruits. Though the sap of fig trees can also induce phytophotodermatitis, it is often poorly recognised. Awareness leads to prevention in order to ensure the safety of gardeners, arborists and forestry workers.

Learning points.

• If a sudden erythematous/bullae rash appears in sun-exposed skin, phytophotodermatitis must be suspected.

• The hyperpigmentation stage may take months to years to resolve.

• Phytophotodermatitis is still poorly recognised among gardeners, arborists, forestry workers and health professionals.