Normally, spring fever—the condition that turns us into restless little bunnies, with the sexual appetite to match—has nothing to do with actual disease. But that’s not a rule it seems Portland theater companies are bothering to heed. Last weekend, six shows opened on stages across the city, all united by a common thread: illness. The onstage ailments run the gamut from physical to psychological, but in each of these six productions, something is definitely amiss. Like amateur physicians, we set out to assess and diagnose what we saw. The general finding? These characters might be ill, but the season’s offerings look vital. 

One Flea Spare

Affliction: Bubonic plague.

Symptoms: Black marks on the neck and hands, violent vomiting, a terrible rotting stench, lunacy.

Diagnosis: The subject of Naomi Wallace's 1995 play might be bodily decay, but in many ways One Flea Spare is driven as much by the mind as by the flesh. It's 1665 in London and a patrician couple, the Snelgraves, have discovered that two rogue individuals—a coarse sailor named Bunce and a 12-year-old girl claiming to be the only surviving member of another wealthy family—have infiltrated their estate. That means all four are subject to another monthlong quarantine, enforced by a lecherous, drunken watchman. As he patrols the periphery, the estate becomes a hothouse of sexual transgression, psychological manipulation and defiance of class hierarchies. Wallace's poetic language can grow frustratingly self-conscious and opaque, so the best moments in this Shaking the Tree production are those that seize the story's baser, more visceral potential. In one scene, Bunce (a mesmerizing Matthew Kerrigan) thrusts an orange onto Mr. Snelgrave's outstretched index finger and then pulls it off, squeezing the fruit's juice into his own mouth. The penetration imagery doesn't stop there. In another psychosexually blunt interaction, Mrs. Snelgrave (Jacklyn Maddux, oozing emotional and physical distress) describes sticking a finger into an open wound below Bunce's belt. Though the play is overwritten and the show overlong, Samantha Van Der Merwe's thoughtful direction still makes this an odd and unsettling study of how the omen of death can pervert all we expect from life. And when the music pulses—the song choices span from M.I.A. to Rage Against the Machine—you've never had so much fun in quarantine. REBECCA JACOBSON. Shaking the Tree Studio, 1407 SE Stark St., 235-0635. 7:30 pm Thursdays-Saturdays and 5 pm Sundays through March 22. $18-$22; Thursdays "pay what you will."

A Small Fire

Affliction: Emily Bridges, a hard-headed and hard-hearted construction boss, slowly takes leave of her senses-—literally. First smell goes, then sight, then hearing. It's like being drunk—but awful.

Symptoms: First depression, then epiphanies, with a protracted slackness in the face preceding each new loss.

Diagnosis: Were Emily—who is openly contemptuous of both her nurturing husband and her daughter's cheese-importing fiance—a more sympathetic character, this would be Lifetime movie territory, a pornography of suffering. But Adam Bock's play is less interested in her pain than her redemption, and her ability to connect with her husband and daughter even as her senses depart. While the staging and movement between scenes is terrifically elegant—a Portland Center Stage hallmark—Rose Riordan's direction seemed a little rushed on opening night, and much of the tense dialogue between Emily (Peggy J. Scott) and her mostly estranged daughter (Hollye Gilbert) was clipped and forced. Scott's tried-on feistiness and belated emoting hit a few too many false notes. As a consequence, the emotional center moves from Emily to Tom Bloom's Mr. Bridges, as he reacts to her plight. His charisma, sadness and simple joys are enough to carry most of the play's water. Still, what's most pivotal to the production's well-being is Bloom's patience: Again and again he deftly moves out of the way of counterparts determined to step on everyone else's lines. So when Emily's naked epiphany finally comes, you don't really want it. You'd rather see her husband sit back in a deck chair and wait for a pack of pigeons. MATTHEW KORFHAGE. Gerding Theater, 128 NW 11th Ave., 445-3700. 7:30 pm Tuesdays-Sundays; 2 pm Saturdays-Sundays; noon Thursdays through March 23. $29-$67.

The Light in the Piazza 

Affliction: Brain trauma.

Symptoms: Kicked in the head by a pony while young, 26-year-old Clara tends to act like a child, joyously shouting "olly olly oxen free!" in a busy cathedral and suffering a hysterical breakdown after getting lost one night in Florence.

Diagnosis: Set in Italy in the early 1950s, Craig Lucas and Adam Guettel's contemporary musical The Light in the Piazza has all the typical elements of a girl-gone-abroad chick flick. There's a happenstance meeting between a bright-eyed American tourist and an attractive Florentine boy who doesn't speak English, their relatives' amusing meddling, and the will-they-or-won't-they drama that ensues. But what distinguishes this Portland Playhouse production is the separate love story that unfolds—the one focused on mother and daughter, as the protective parent learns to let go. The music, played simply and beautifully on piano and cello, can be near-operatic, with lyrics in both English and Italian. Non-Italian speakers have nothing to fear: The performers' clever asides and facial gestures help reveal meaning, allowing the two languages to shift in and out of each other as easily as the small set is transformed from an Italian cathedral to a hotel room. Supported by a top-notch cast, Susannah Mars and Merideth Kaye Clark work off each other easily. As the mother, Mars captures a sternness that quickly melts into sadness when remembering a past love or when tucking an upset Clara into bed. Clark just as skillfully embodies Clara's bright curiosity and passion as she runs around stage, smiling and dancing at the wind and the flowers, or crying and raging at her mother for saying "no." These relatable moments of unconditional love often shine over a more traditional—though still very sweet—romance. KAITIE TODD. Portland Playhouse, 602 NE Prescott St., 488-5822. 7:30 pm Wednesdays-Saturdays and 2 pm Sundays through March 30. $32-$36.

The Motherfucker With the Hat 

Affliction: Drug addiction.

Symptoms: Most of the characters in Stephen Adly Guirgis' 2011 comedy are drug addicts. Three are in recovery, but that doesn't mean they're any less unhinged.

Diagnosis: As The Motherfucker With the Hat opens, main character Jackie (John San Nicolas), a recovering drug addict on parole, enters his bare-bones apartment with near-boundless energy. He's landed a job and feels buoyed by the promise of a fresh start for himself and his childhood sweetheart Veronica (Diana DeLaCruz). But that fades when he notices an unfamiliar man's hat on the coffee table. It's like "motherfucking Zorro leaving his Z" all over the place, and Jackie slumps into an emasculated wreck. With his bad-boy carriage and fiery eloquence, Jackie bumbles through entertaining tantrums on his search for the titular motherfucker, relying on his AA sponsor Ralph (Victor Mack) and cousin Julio (Gilberto Martin del Campo, infectiously hilarious). As the plot develops and real drama unfolds, though, the script's perky sarcasm becomes tedious, and Ralph's eruptions grow tiresome. Yet this Artists Rep production, directed by Kevin Jones, still manages to tell a surprisingly lighthearted and often very funny story of drug abuse. It's most effective when highlighting how addiction tips the power dynamics between lovers or sponsors and sponsees. In a strong cast, Val Landrum gives an especially moving performance as Victoria, Ralph's ex-sponsee and unhappy wife. When she comes onto Jackie after getting drunk and high, she confesses her regrets with the pained insight of a longtime addict and then strokes his neck, as mournful as she is desperate. LAUREN TERRY. Artists Repertory Theatre, 1515 SW Morrison St., 241-1278. 7:30 pm Wednesdays-Sundays and 2 pm Sundays through March 30. $25-$55.

King Lear

Affliction: In the words of Lear himself, "O, that way madness lies."

Symptoms: Figurative blindness in the case of Lear, who's blinded by his insanity. And literal blindness in the case of the Earl of Gloucester, whose eyes are plucked from his head.

Diagnosis: This compelling Northwest Classical Theatre production—directed by JoAnn Johnson and set on a thrust stage with seating for only 38—draws its audience into a chaotic land ruled by sickness and madness. Power is to be divided among Lear's three daughters: Goneril (Melissa Whitney), Regan (Brenan Dwyer) and Cordelia (Clara-Liis Hillier). They're equals in beauty, but only Cordelia embodies purity and filial obedience. King Lear (Ted Roisum) speaks with a booming voice, making the audience jump to attention. Roisum first plays Lear as an infuriated, rigid man who shakes his cane at his "thankless children." He demands devotion from his daughters and expresses his discontent with Cordelia's simple adoration by scowling and sneering at her. But as the play progresses, Lear becomes something of an innocent babe who recognizes his cruelty and inevitable mortality. The impeccable costuming conveys a character's purity or wickedness—white glittering robes for Cordelia, red for Lear, and opulent purple and green for the greedy Regan and Goneril. KATHRYN PEIFER. Shoe Box Theater, 2110 SE 10th Ave., 971-244-3740. 7:30 pm Thursdays-Saturdays and 2 pm Sundays through March 30. $18-$20.

The Caretaker 

Affliction: Mental illness, self-delusion, general remove from reality.

Symptoms: In Harold Pinter's 1960 masterpiece, all three characters experience some sort of mental plight. Aston is detached and cognitively sluggish due to electroshock therapy. His brother Mick is a batty sociopath. And then there's Davies, the coughing, stinking vagabond they bring home.

Diagnosis: You think you can lay down anything as reductive as a diagnosis on a Pinter play? The Caretaker scarcely has a plot: A tramp stays at a fetid London flat—evocatively rendered here with water-stained walls, piles of paper and a discarded shopping cart—and interacts with two brothers in ways alternately mundane and bizarre. Younger brother Mick (Jeffrey Jason Gilpin) is a neon-hued maniac clad in orange and lavender, his hair a slicked-back, bleach-blond helmet. He darts about the stage like a razor, his moods and motives shifting like quicksilver. As the dark-haired, lumbering Aston, meanwhile, Jacob Coleman moves as if in slow-motion. But the real star of this Imago production is a near-unrecognizable Allen Nause, a twitchy, stuttering lump buried under dirty rags. Nause imbues the character with underlying sadness and wicked humor, whether he's modeling a ridiculous-looking burgundy smoking jacket or insisting on matching laces for the shoes he's been gifted. Davies might be a foul-mouthed, racist ingrate, but in Nause's hands, he's profoundly human. Swiveling from scabrously comic to deeply haunting, this production solves no mysteries and heals no wounds. Which is probably the way Pinter would have wanted it—if he ever would have said as much. REBECCA JACOBSON. Imago Theatre, 17 SE 8th Ave., 231-9581. 7 pm Thursdays and Sundays and 8 pm Fridays-Saturdays through March 23 (no show March 6). $17-$25.