Phytophotodermatitis is a cutaneous reaction caused by direct contact with phototoxic agents and subsequent sunlight exposure. Furocoumarins and psoralens are 2 phototoxic agents that can cause this reaction, and these organic chemical compounds are found in many plant species consumed by humans. Following contact exposure to such foods and ultraviolet radiation exposure via direct sunlight, phytophotodermatitis can occur. Due to the etiology of these rashes relating closely to the outdoor consumption of margaritas, the rash may be known by patients as "margarita burn." There is a classically described sequence of rash progression: erythematous macules or patches, which later become vesicles and seem similar to second-degree burns, followed by an asymptomatic hyperpigmentation. This case presents a 26-year-old female diagnosed with phytophotodermatitis following use of citrus fruits for margaritas while outdoors in direct sunlight. The diagnosis of phytophotodermatitis is often made clinically but can be complicated due to its similarity in appearance to many other common cutaneous reactions. In this patient, the differential diagnosis included solar erythema, contact dermatitis (type IV hypersensitivity reaction), polymorphic light eruption, or drug-related photosensitivity. Careful history taking is essential in not only narrowing down the differential diagnosis but also in avoiding unnecessary tests or ineffective treatments.

Many cases of viral meningitis are idiopathic, but increased utilization of polymerase chain reaction testing has enabled physicians to better recognize rare causes of viral meningitis. This will likely continue to improve the rate of causative agent identification in seemingly idiopathic viral meningitis, including this case of human herpesvirus 6 (HHV-6) meningitis in an immunocompetent adult patient. More common viral etiologies need to be excluded before diagnosing HHV-6 meningitis, as this maximizes pretest probability and therefore increases validity of a positive result. By efficiently diagnosing HHV-6 meningitis, proper treatment protocols can be initiated earlier to reduce morbidity and mortality. Given the rarity of HHV-6 meningitis in immunocompetent adults, there are no established standard treatment guidelines; previous reported cases, as well as this case, suggest that either intravenous ganciclovir or intravenous foscarnet are the most reasonable first-line treatment options.